Intelligent tracking system and methods and systems therefor

ABSTRACT

An intelligent tracking system generally includes one or more tracking devices, some of which may be passive tracking devices. Each passive tracking device includes one or more transceivers and is energized by an energizing signal. Some of these passive tracking devices may operate in a first communication mode or a second communication mode based on the energizing signal. Some tracking devices may include encryption modules or authentication modules. Some of these devices may incorporate a bulk acoustic wave oscillator.

PRIORITY CLAIM

This application is a bypass continuation of International Pat. App. No.PCT/US2019/034975 filed on May 31, 2019, which claims priority to U.S.Provisional Patent Application No. 62/679,327 filed on Jun. 1, 2018entitled “INTELLIGENT TRACKING SYSTEM AND METHODS AND SYSTEMS THEREFOR”,U.S. Provisional Patent Application No. 62/771,320 filed on Nov. 26,2018 entitled “INTELLIGENT TRACKING SYSTEM AND METHODS AND SYSTEMSTHEREFOR”, and U.S. Provisional Patent Application No. 62/812,442 filedon Mar. 1, 2019 entitled “INTELLIGENT TRACKING SYSTEM AND METHODS ANDSYSTEMS THEREFOR”, the contents of which are all herein incorporated byreference in their entirety.

FIELD

The present disclosure relates to an intelligent tracking systemincluding a tracking system and a backend server system that supportsthe tracking system. The disclosure further relates to differentconfigurations of devices that may be used in the tracking system,including configurations of powered tracking devices, passive trackingdevices, and aggregator devices that may be used in a tracking system.

BACKGROUND

Tracking devices are used to track various items. Typically a trackingdevice includes a GPS module. GPS modules may be power hungry. As such,typical tracking devices need constant powering and are therefore,ill-suited for tracking shipments on long routes (e.g., ship, train, andlong-distance truck). GPS modules may also be expensive. As such,typical tracking devices cannot be used to track many items due to thecosts associated with placing a large amount of tracking devices in asingle shipment or on a group of items. GPS modules may also be large.As such, typical tracking devices may be ill-suited for tracking smalleritems. Furthermore, while small tracking tags can be used for trackingsmaller items, most of these tags rely on the use of cellular modems andinclude batteries and can be rather expensive.

SUMMARY

According to some embodiments of the present disclosure, a passivetracking device is disclosed. The passive tracking device includes afirst antenna that transmits first response signals in a first frequencyband, a second antenna that receives first energizing signals in asecond frequency band, and a third antenna that both transmits secondresponse signals and receives second energizing signals in a thirdfrequency band. The passive tracking device further includes an energyharvest module that receives an energizing signal from a remote devicevia the second antenna and/or the third antenna, and converts theenergizing signal from RF electrical energy to DC electrical energy thatenergizes the passive tracking device. The passive tracking devicefurther includes a first transmission module that modulates a firstresponse signal for transmission in the first frequency band and outputsthe modulated first response signal to the first antenna fortransmission when the passive tracking device operates in a first modein accordance with a first communication protocol, wherein the firstresponse signal includes a first message indicating a first deviceidentifier of the passive tracking device. The passive device alsoincludes a second transmission module that prepares a second responsesignal for transmission in the third frequency band and facilitatestransmission of the prepared second response signals by togglingimpedance of the third antenna when the passive tracking device operatesin a second mode in accordance with a second communication protocol. Thesecond response signal includes a second message indicating a seconddevice identifier of the passive tracking device. The passive trackingdevice also includes a mode selection module that determines whether thepassive tracking device is to operate in the first mode or the secondmode based on the energizing signal.

In embodiments, the first communication protocol is one of a Bluetooth,Bluetooth Low Energy, or Wi-Fi communication protocol and the firstfrequency band is suitable for carrying signals in accordance with theone of Bluetooth, Bluetooth Low Energy, or Wi-Fi communication protocol.In these embodiments, the second frequency band is equal to the firstfrequency band, the second communication protocol is an RFIDcommunication protocol, and the third frequency band is suitable forcarrying signals in accordance with the RFID communication protocol. Insome of these embodiments, the first frequency band and the secondfrequency band are substantially equal to 2.4 GHz and the thirdfrequency band is substantially equal to 900 MHz. In some embodiments,the second communication protocol is an EPC UHF RFID communicationprotocol.

In embodiments, the passive tracking device modulates and transmits thefirst response signals according to one of a Bluetooth communicationprotocol, a Bluetooth Low Energy communication protocol, and a Wi-Ficommunication protocol while operating in the first mode, and preparesand transmits the second response signals according to an RFIDcommunication protocol while operating in the second mode. In some ofthese embodiments, the mode selection module determines to modulate andtransmit the first response signals according to the Bluetooth LowEnergy protocol as a default, unless the energizing signal is receivedon the third frequency band and contains a recognized RFID command.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the first mode in response to receivingenergizing signals in the second frequency band via the second antenna.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the first mode in response todetermining that the energizing signal received does not contain an RFIDheader or command. In some of these embodiments, the first modeselection module determines that the passive tracking device is tooperate in the first mode in response to determining that the energizingsignal received does not contain an EPC UHF RFID header or command.

In embodiments, the first transmission module determines when thepassive tracking device is to transmit the modulated first responsesignal based on an amount of energy stored by the passive trackingdevice. In some of these embodiments, the first transmission moduledetermines that the passive tracking device is to transmit the modulatedfirst response signal substantially immediately when the amount ofenergy stored by the passive tracking device exceeds a first powerthreshold. In some of these embodiments, the first transmission moduledetermines that the passive tracking device is to transmit the modulatedfirst response signal after a delay when the amount of energy stored bythe passive tracking device exceeds a second power threshold and is lessthan the first power threshold, the second power threshold being lessthan the first power threshold. In some of these embodiments, the firstpower threshold is 0 dBm and the second power threshold is −20 dBm.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the second mode in response toreceiving energizing signals in the third frequency band via the thirdantenna.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the second mode based on contents ofthe energizing signal. In these embodiments, the mode selection moduledetermines that the passive tracking device is to operate in the secondmode in response to determining that the energizing signal includes anRFID-formatted header. In some embodiments, the mode selection moduledetermines that the passive tracking device is to operate in the secondmode in response to the energizing signals received containing acomplete RFID-formatted message.

In embodiments, the first mode is a default mode of transmission and thesecond mode is selected by the mode selection module in response toreceiving the energizing signal in the third frequency band via thethird antenna and the energizing signal containing an RFID-formattedheader and a complete RFID-formatted message containing an EPC command.In some embodiments, the energy harvest module outputs the DC electricalenergy to one or more of first and second transmission modules and themode selection module. In some embodiments, the first device identifierand the second device identifier are the same.

In embodiments, the passive tracking device further includes a sensormodule, the sensor module including one or more sensors, wherein thesensor module outputs sensor data generated by the one or more sensorsto the first transmission module when the passive tracking deviceoperates in the first mode and the first transmission module includes atleast a portion of the sensor data in the modulated first responsesignal for transmission via the first antenna. In some embodiments, theone or more sensors include one or more of a temperature sensor, a lightsensor, a sound sensor, a humidity sensor, a motion sensor, a shocksensor, and an acceleration sensor. In some embodiments, the firsttransmission module includes at least a portion of the sensor data inthe modulated first response signal for transmission via the firstantenna when a value of the sensor data satisfies a predefinedcondition. In some of these embodiments, the first transmission moduleincludes a temperature value obtained from a temperature sensor in thefirst response signal when the temperature value exceeds an upperthreshold. In some embodiments, the first transmission module includes atemperature value obtained from a temperature sensor in the firstresponse signal when the temperature value is less than a lowerthreshold. In some embodiments, the first transmission module includessensor data generated by the one or more sensors in the first responsesignals when a value of the sensor data has met and/or exceeded athreshold. In some of these embodiments, the first transmission modulerefrains from including the sensor data in the first response signalwhen the predefined condition is not satisfied by the sensor data.

In embodiments, the passive tracking device includes an encryptionmodule that encrypts messages and outputs the encrypted messages to thefirst transmission module when the passive tracking device communicatesin the first mode and the first transmission module includes at least aportion of the encrypted messages in the modulated first response signalfor transmission via the first antenna. In some embodiments, theencryption module encrypts the first device identifier of the passivetracking device based on a secret pattern and a secret key to obtain anencrypted message and outputs the encrypted message to the firsttransmission module.

In embodiments, the energy harvest module includes a transformer thatsubstantially matches impedance of the energizing signals to the passivetracking device.

According to some embodiments of the present disclosure, a passivetracking device is disclosed. The passive tracking device includes afirst antenna that transmits first response signals in a first frequencyband, a second antenna that receives first energizing signals in asecond frequency band, and a third antenna that both transmits secondresponse signals and receives second energizing signals in a thirdfrequency band. The passive tracking device further includes an energyharvester that receives an energizing signal from a remote device viathe second antenna and/or the third antenna and at least partiallyconverts the energizing signal from RF electrical energy to DCelectrical energy. The passive tracking device also includes a clampcircuit that receives the energizing signal from the energy harvesterand at least partially converts the energizing signal from the RFelectrical energy to the DC electrical energy together with the energyharvester. The passive tracking device further includes a storagecapacitor that receives the DC electrical energy from the clamp circuitand stores the DC electrical energy, and a voltage regulator thatreceives the DC electrical energy from one or both of the clamp circuitand the storage capacitor, and regulates voltage of the DC electricalenergy. The passive tracking device also includes a power bus thatreceives the regulated DC electrical energy from the voltage regulatorand energizes the passive tracking device, and a phase-locked loop thatmodulates a first response signal for transmission in the firstfrequency band and outputs the modulated first response signal to thefirst antenna for transmission when the passive tracking device operatesin a first mode in accordance with a first communication protocol,wherein the first response signal includes a first message indicating afirst device identifier of the passive tracking device. The passivetracking device also includes an amplifier that receives the modulatedfirst response signal from the phase-locked loop and amplifies themodulated first response signal for transmission via the first antenna,and an AC power source that provides signals to the phase-locked loopfor modulation. The passive tracking device also includes a referenceoscillator that provides a reference frequency to the AC power source,and a Gaussian frequency shift keying modulator that works with thephase-locked loop to modulate first response signal. The passivetracking device further includes a state machine that outputsinformation to the Gaussian frequency shift keying modulator forinclusion in modulated first response signal, and a non-volatile memorythat stores information that is available for retrieval by the statemachine and inclusion in the modulated first response signal. Thepassive tracking device also includes a backscatter switch that preparesa second response signal for transmission in the third frequency bandand facilitates transmission of the prepared second response signals bytoggling impedance of the third antenna when the passive tracking deviceoperates in a second mode in accordance with a second communicationprotocol, wherein the second response signal includes a second messageindicating a second device identifier of the passive tracking device.The passive tracking device also includes an EPC modem that actuates thebackscatter switch to prepare the second response signal, and a modeselector that receives an energizing signal from the second antenna orthe third antenna and determines whether the passive tracking device isto operate in the first mode or the second mode based on the energizingsignal.

In embodiments the first communication protocol is one of a Bluetooth,Bluetooth Low Energy, or Wi-Fi communication protocol, the firstfrequency band is suitable for carrying signals in accordance with theone of Bluetooth, Bluetooth Low Energy, or Wi-Fi communication protocol,the second frequency band is equal to the first frequency band, thesecond communication protocol is an RFID communication protocol, and thethird frequency band is suitable for carrying signals in accordance withthe RFID communication protocol. In some of these embodiments, the firstfrequency band and the second frequency band are substantially equal to2.4 GHz and the third frequency band is substantially equal to 900 MHz.

In embodiments, the second communication protocol is an EPC UHF RFIDprotocol communication protocol. In some embodiments, the passivetracking device modulates and transmits the first response signalsaccording to one of a Bluetooth communication protocol, a Bluetooth LowEnergy communication protocol, and a Wi-Fi communication protocol whileoperating in the first mode, and prepares and transmits the secondresponse signals according to RFID while operating in the second mode.In some embodiments, the mode selection module determines to modulateand transmit the first response signals according to the Bluetooth LowEnergy protocol as a default, unless the energizing signal is receivedon the third frequency band and contains a recognized RFID command. Insome embodiments, the mode selector determines that the passive trackingdevice is to operate in the first mode in response to receiving theenergizing signal in the second frequency band via the second antenna.In some embodiments, the mode selector determines that the passivetracking device is to operate in the first mode in response todetermining that the energizing signal does not contain an RFID headeror command. In some embodiments, the mode selector determines that thepassive tracking device is to operate in the first mode in response todetermining that the energizing signal does not contain an EPC UHF RFIDheader or command.

In embodiments, the state machine determines when the passive trackingdevice is to transmit the modulated first response signal based on anamount of energy stored by the storage capacitor. In some of theseembodiments, the state machine determines that the passive trackingdevice is to transmit the modulated first response signal substantiallyimmediately when the amount of energy stored by the storage capacitorexceeds a first power threshold. In some embodiments, the state machinedetermines that the passive tracking device is to transmit the modulatedfirst response signal after a delay when the amount of energy stored bythe storage capacitor exceeds a second power threshold and is less thanthe first power threshold, the second power threshold being less thanthe first power threshold. In some of these embodiments, the first powerthreshold is 0 dBm and the second power threshold is −20 dBm.

In embodiments, the mode selector determines that the passive trackingdevice is to operate in the second mode in response to receiving theenergizing signal in the third frequency band via the third antenna. Insome embodiments, the mode selector determines that the passive trackingdevice is to operate in the second mode based on contents of theenergizing signal. In some of these embodiments, the mode selectordetermines that the passive tracking device is to operate in the secondmode in response to determining that the energizing signal includes anRFID-formatted header. In some embodiments, the mode selector determinesthat the passive tracking device is to operate in the second mode inresponse to the energizing signals received containing a completeRFID-formatted message.

In embodiments, the mode selector determines that the passive trackingdevice is to operate in the second mode in response to an amount ofenergy converted from the energizing signal by the energy harvester andthe clamp circuit. In some embodiments, the first mode is a default modeof transmission and the second mode is selected by the mode selector inresponse to receiving energizing signals in the third frequency band viathe third antenna, and the energizing signal containing anRFID-formatted header and a complete RFID-formatted message containingan EPC command. In some embodiments, the power bus transmits the DCelectrical energy to one or more of first and second transmissionmodules and the mode selector. In some embodiments, the first deviceidentifier and the second device identifier are the same.

In embodiments, the passive tracking device further includes a sensormodule. The sensor module includes one or more sensors. The sensormodule outputs sensor data generated by the one or more sensors to thestate machine and/or the non-volatile memory when the passive trackingdevice operates in the first mode and the state machine includes atleast a portion of the sensor data in the modulated first responsesignal for transmission via the first antenna. In some embodiments, theone or more sensors include one or more of a temperature sensor, a lightsensor, a sound sensor, a humidity sensor, a motion sensor, a shocksensor, and an acceleration sensor. In some of these embodiments, thestate machine includes at least a portion of the sensor data in themodulated first response signal for transmission via the first antennawhen a value of the sensor data satisfies a predefined condition. Insome embodiments, the state machine includes a temperature valueobtained from a temperature sensor in the first response signal when thetemperature value exceeds an upper threshold. In some of theseembodiments, the state machine includes a temperature value obtainedfrom a temperature sensor in the first response signal when thetemperature value is less than a lower threshold.

In embodiments, the sensor module outputs sensor data generated by theone or more sensors to the state machine and/or the non-volatile memorywhen a value of the sensor data has met and/or exceeded a threshold. Insome embodiments, the state machine refrains from including the sensordata in the first response signal when the predefined condition is notsatisfied by the sensor data.

In embodiments, the passive tracking device further includes anencryption module that encrypts messages and outputs the encryptedmessages to the state machine when the passive tracking devicecommunicates in the first mode, and the state machine includes at leasta portion of the encrypted messages in the modulated first responsesignal for transmission via the first antenna. In some embodiments, theencryption module encrypts the first device identifier of the passivetracking device based on a secret pattern and a secret key to obtain anencrypted message and outputs the encrypted message to the statemachine.

In embodiments, the reference oscillator is a bulk acoustic waveoscillator.

In embodiments, the passive tracking device further includes atransformer connected to the second antenna and the energy harvesterthat substantially matches impedance of energizing signals received viathe second antenna to the passive tracking device and outputs theimpedance matched energizing signal to the energy harvester.

According to some embodiments of the present disclosure, a passivetracking device is disclosed. The passive tracking device includes afirst antenna that transmits response signals in a first frequency band,and a second antenna that receives energizing signals in a secondfrequency band. The passive tracking device further includes an energyharvest module that receives an energizing signal from a remote devicevia the second antenna and converts the energizing signal from RFelectrical energy to DC electrical energy that energizes the passivetracking device. The passive tracking device also includes atransmission module that modulates a response signal for transmission inthe first frequency band and outputs the modulated response signal tothe first antenna for transmission in accordance with a communicationprotocol, wherein the response signal includes a message indicating adevice identifier of the passive tracking device. The passive trackingdevice further includes a sensor module including one or more sensors.In response to being energized by the energy harvest module, the sensormodule outputs sensor data generated by the one or more sensors to thetransmission module and the transmission module includes at least aportion of the sensor data in the modulated response signal fortransmission via the first antenna.

In embodiments, the one or more sensors include one or more of atemperature sensor, a light sensor, a sound sensor, a humidity sensor, amotion sensor, a shock sensor, and an acceleration sensor.

In embodiments, the transmission module includes at least a portion ofthe sensor data in the modulated response signal when a value of thesensor data satisfies a predefined condition. In some embodiments, thetransmission module includes a temperature value obtained from atemperature sensor in the modulated response signal when the temperaturevalue exceeds an upper threshold. In some embodiments, the transmissionmodule includes a temperature value obtained from a temperature sensorin the modulated response signal when the temperature value is less thana lower threshold. In some embodiments, the transmission module includessensor data generated by the one or more sensors in the modulatedresponse signal when a value of the sensor data has met and/or exceededa threshold. In some embodiments, the transmission module refrains fromincluding the sensor data in the response signal when the predefinedcondition is not satisfied by the sensor data.

In embodiments, the transmission module is a first transmission module,the response signals are first response signals, the energizing signalsare first energizing signals, the communication protocol is a firstcommunication protocol, the message is a first message, and the deviceidentifier is a first device identifier. In some of these embodiments,the first transmission module modulates the first response signal andoutputs the modulated response signal to the first transmission modulewhen the passive tracking device operates in a first mode, and thesensor module outputs sensor data to the first transmission module whenthe passive tracking device operates in the first mode.

In embodiments, the passive tracking device further includes a thirdantenna that both transmits second response signals and receives secondenergizing signals in a third frequency band, and a second transmissionmodule that prepares a second response signal for transmission in thethird frequency band and facilitates transmission of the prepared secondresponse signals by toggling impedance of the third antenna when thepassive tracking device operates in a second mode in accordance with asecond communication protocol. The second response signal includes asecond message indicating a second device identifier of the passivetracking device. The passive tracking device also includes a modeselection module that determines whether the passive tracking device isto operate in the first mode or the second mode based on a receivedenergizing signal from a remote device via the second antenna and/or thethird antenna.

In embodiments, the first communication protocol is one of a Bluetooth,Bluetooth Low Energy, or Wi-Fi communication protocol. The firstfrequency band is suitable for carrying signals in accordance with theone of Bluetooth, Bluetooth Low Energy, or Wi-Fi communication protocol.The second frequency band is equal to the first frequency band. Thesecond communication protocol is an RFID communication protocol. Thethird frequency band is suitable for carrying signals in accordance withthe RFID communication protocol. In some embodiments, the firstfrequency band and the second frequency band are substantially equal to2.4 GHz and the third frequency band is substantially equal to 900 MHz.In some of these embodiments, the second communication protocol is anEPC UHF RFID communication protocol.

In embodiments, the passive tracking device modulates and transmits thefirst response signals according to one of a Bluetooth communicationprotocol, a Bluetooth Low Energy communication protocol, and a Wi-Ficommunication protocol while operating in the first mode, and preparesand transmits the second response signals according to RFID whileoperating in the second mode. In some embodiments, the mode selectionmodule determines to modulate and transmit the first response signalsaccording to the Bluetooth Low Energy protocol as a default, unless theenergizing signal is received on the third frequency band and contains arecognized RFID command. In some embodiments, the mode selection moduledetermines that the passive tracking device is to operate in the firstmode in response to receiving energizing signals in the second frequencyband via the second antenna.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the first mode in response todetermining that the energizing signal received does not contain an RFIDheader or command. In some of these embodiments, the first modeselection module determines that the passive tracking device is tooperate in the first mode in response to determining that the energizingsignal received does not contain an EPC UHF RFID header or command.

In embodiments, the first transmission module determines when thepassive tracking device is to transmit the modulated first responsesignal based on an amount of energy stored by the passive trackingdevice. In some of these embodiments, the first transmission moduledetermines that the passive tracking device is to transmit the modulatedfirst response signal substantially immediately when the amount ofenergy stored by the passive tracking device exceeds a first powerthreshold. In some embodiments, the first transmission module determinesthat the passive tracking device is to transmit the modulated firstresponse signal after a delay when the amount of energy stored by thepassive tracking device exceeds a second power threshold and is lessthan the first power threshold, the second power threshold being lessthan the first power threshold. In some embodiments, the first powerthreshold is 0 dBm and the second power threshold is −20 dBm.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the second mode in response toreceiving energizing signals in the third frequency band via the thirdantenna.

In embodiments, the mode selection module determines that the passivetracking device is to operate in the second mode based on contents ofthe energizing signal. In some embodiments, the mode selection moduledetermines that the passive tracking device is to operate in the secondmode in response to determining that the energizing signal includes anRFID-formatted header. In some embodiments, the mode selection moduledetermines that the passive tracking device is to operate in the secondmode in response to the energizing signals received containing acomplete RFID-formatted message.

In embodiments, the first mode is a default mode of transmission and thesecond mode is selected by the mode selection module in response toreceiving the energizing signal in the third frequency band via thethird antenna, and the energizing signal containing an RFID-formattedheader and a complete RFID-formatted message containing an EPC command.

In embodiments, the energy harvest module outputs the DC electricalenergy to one or more of first and second transmission modules and themode selection module. In embodiments, the first device identifier andthe second device identifier are the same.

In embodiments, the sensor module includes a bulk acoustic wavetemperature sensor.

In embodiments, the transmission module includes a reference oscillatorthat is a bulk acoustic wave oscillator.

According to some embodiments of the present disclosure, a trackingdevice is disclosed. The tracking device includes a first antenna thattransmits response signals in a first frequency band. The trackingdevice also includes a transmission module that modulates a responsesignal for transmission in the first frequency band and outputs themodulated response signal to the first antenna for transmission inaccordance with a communication protocol. The tracking device furtherincludes an encryption module. The encryption module obtains a deviceidentifier that uniquely identifies the tracking device, generates anobscured device identifier based on the device identifier and a secretpattern, generates a message based on the obscured device identifier,encrypts the message using a secret key to obtain an encrypted message,and outputs the encrypted message to the transmission module. Thetransmission module includes the encrypted message in the modulatedresponse signal for transmission via the first antenna.

In embodiments, generating the obscured device identifier includesgenerating a random N-bit string and inserting the random N-bit stringinto the device identifier according to the secret pattern. In some ofthese embodiments, the secret pattern defines N different insertionslots, wherein each insertion slot respectively defines a bit positionof the device identifier where a respective bit of the random N-bitstring is inserted. In some embodiments, an authentication devicedecrypts the message using the secret key to obtain the obscured deviceidentifier, and authenticates the tracking device by removing the randomN-bit string from the decrypted message to obtain the device identifierof the tracking and verifying the device identifier from a list of knowndevice identifiers.

In embodiments, the encrypted message includes an encrypted portion andan unencrypted portion, the unencrypted portion including a secret keyidentifier that identifies the secret key to an authentication device.In some of these embodiments, the authentication device retrieves thesecret key based on the secret key identifier and decrypts the encryptedmessage using the secret key. In some embodiments, the encrypted messagefurther includes a secret pattern identifier that identifies the secretpattern to the authentication device. In some of these embodiments, thesecret pattern is included in the unencrypted portion of the encryptedmessage. In some embodiments, the secret pattern is included in theencrypted portion of the encrypted message.

In embodiments, the tracking device is a passive tracking device that isenergized upon receiving an energizing signal from a remote device. Insome of these embodiments, the response signal is received by a readingdevice, which in turn transmits the encrypted message contained thereinto an authentication device that authenticates the tracking device basedon the encrypted message, the secret key, and the secret pattern. Insome embodiments, the passive tracking device is a dual-mode trackingdevice that selectively operates in a first mode and a second mode basedon the frequency band of the energizing signal and contents of theenergizing signal. In embodiments, the encryption module generates theencrypted message only when the dual-mode tracking device operates inthe first mode. In some embodiments, the first mode corresponds to aBluetooth Low Energy communication protocol and the second modecorresponds to RFID communication protocol.

In embodiments, the tracking device includes a power source. In some ofthese embodiments, the tracking device transmits the encrypted messageto an authentication device directly.

In embodiments, the tracking device is authenticated by anauthentication device based on the encrypted message, the secretpattern, and the secret key. In some of these embodiments, theauthenticating device is an authentication server that authenticatestracking devices.

According to some embodiments of the present disclosure, a method forgenerating encrypted messages that are used to authenticate a trackingdevice by an authentication device is disclosed. The method includesobtaining, by an encryption module of the passive tracking device adevice identifier that uniquely identifies the tracking device. Themethod also includes generating, by the encryption module, an obscureddevice identifier based on the device identifier and a secret pattern.The method further includes generating, by the encryption module, amessage based on the obscured device identifier. The method alsoincludes encrypting, by the encryption module, the message using asecret key to obtain an encrypted message. The method further includesoutputting, by the encryption module, the encrypted message to atransmission module of the tracking device. The method further includesmodulating, by the transmission module, a response signal that includesthe encrypted message for transmission via an antenna of the trackingdevice.

In embodiments, generating the obscured device identifier includesgenerating a random N-bit string and inserting the random N-bit stringinto the device identifier according to the secret pattern. In someembodiments, the secret pattern defines N different insertion slots,wherein each insertion slot respectively defines a bit position of thedevice identifier where a respective bit of the random N-bit string isinserted. In some embodiments, an authentication device decrypts themessage using the secret key to obtain the obscured device identifier,and authenticates the tracking device by removing the random N-bitstring from the decrypted message to obtain the device identifier of thetracking and verifying the device identifier from a list of known deviceidentifiers.

In embodiments, the encrypted message includes an encrypted portion andan unencrypted portion, the unencrypted portion including a secret keyidentifier that identifies the secret key to an authentication device.In some of these embodiments, the authentication device retrieves thesecret key based on the secret key identifier and decrypts the encryptedmessage using the secret key. In some embodiments, the encrypted messagefurther includes a secret pattern identifier that identifies the secretpattern to the authentication device. In some embodiments, the secretpattern is included in the unencrypted portion of the encrypted message.In some embodiments, the secret pattern is included in the encryptedportion of the encrypted message.

In embodiments, the tracking device is a passive tracking device that isenergized upon receiving an energizing signal from a remote device. Insome of these embodiments, the response signal is received by a readingdevice, which in turn transmits the encrypted message contained thereinto an authentication device that authenticates the tracking device basedon the encrypted message, the secret key, and the secret pattern. Insome embodiments, the passive tracking device is a dual-mode trackingdevice that selectively operates in a first mode and a second mode basedon the frequency band of the energizing signal and contents of theenergizing signal. In some embodiments, the encryption module generatesthe encrypted message only when the dual-mode tracking device operatesin the first mode. In some embodiments, the first mode corresponds to aBluetooth Low Energy communication protocol and the second modecorresponds to RFID communication protocol.

In embodiments, the tracking device includes a power source. In some ofthese embodiments, the tracking device transmits the encrypted messageto an authentication device directly.

In embodiments, the tracking device is authenticated by anauthentication device based on the encrypted message, the secretpattern, and the secret key. In some of these embodiments, theauthenticating device is an authentication server that authenticatestracking devices. In some embodiments, the authenticating device is anaggregator device. In some embodiments, the authenticating device is abackend server system. In some embodiments, the authenticating device isa user device.

According to some embodiments of the present disclosure, a system forauthenticating tracking devices is disclosed. The system includes atracking device that generates an encrypted message that indicates atracking identifier that uniquely identifies the tracking device andmodulates a response signal that includes the encrypted message fortransmission via an antenna of the tracking device. The system alsoincludes an authentication server that receives the encrypted message,determines the device identifier based on the encrypted message, andverifies the device identifier based on a list of known deviceidentifiers, wherein the list of known device identifiers indicatesdevice identifiers of valid tracking devices.

In embodiments, the tracking device includes an encryption module. Theencryption module generates an obscured device identifier based on thedevice identifier and a secret pattern. The encryption module alsogenerates a message based on the obscured device identifier. Theencryption module further encrypts the message using a secret key toobtain the encrypted message, and outputs the encrypted message to thetransmission module.

In embodiments, generating the obscured device identifier includesgenerating a random N-bit string and inserting the random N-bit stringinto the device identifier according to the secret pattern. In some ofthese embodiments, the secret pattern defines N different insertionslots, wherein each insertion slot respectively defines a bit positionof the device identifier where a respective bit of the random N-bitstring is inserted. In some embodiments, the authentication devicedecrypts the encrypted message using the secret key to obtain theobscured device identifier, and determines the device identifier of thetracking device by removing the random N-bit string from the decryptedmessage.

In embodiments, the encrypted message includes an encrypted portion andan unencrypted portion, the unencrypted portion including a secret keyidentifier that identifies the secret key to the authentication device.In some of these embodiments, the authentication device retrieves thesecret key based on the secret key identifier and decrypts the encryptedmessage using the secret key. In some embodiments, the encrypted messagefurther includes a secret pattern identifier that identifies the secretpattern to the authentication device. In some of these embodiments, thesecret pattern is included in the unencrypted portion of the encryptedmessage. In some embodiments, the secret pattern is included in theencrypted portion of the encrypted message.

In embodiments, the system further includes a reading device. Thereading device receives the response signal from the tracking device,and transmits the encrypted message contained in the response signal tothe authentication server via a communication network. In some of theseembodiments, the tracking device is a passive tracking device and thereading device broadcasts an energizing signal that energizes thepassive tracking device. In some embodiments, the passive trackingdevice is a dual-mode tracking device that selectively operates in afirst mode and a second mode based on the frequency band of theenergizing signal and contents of the energizing signal. In some ofthese embodiments, the encryption module generates the encrypted messageonly when the dual-mode tracking device operates in the first mode. Insome embodiments, the first mode corresponds to a Bluetooth Low Energycommunication protocol and the second mode corresponds to RFIDcommunication protocol.

In embodiments, the tracking device includes a power source. In some ofthese embodiments, the tracking device transmits the encrypted messageto an authentication device directly. In some embodiments, theauthentication server confirms a presence of the tracking device in ageneral location based on the encrypted message.

According to some embodiments of the present disclosure, the passivetracking device is disclosed. The passive tracking device includes afirst antenna that transmits response signals in a first frequency bandand a second antenna that receives energizing signals in a secondfrequency band. The passive tracking device also includes an energyharvest module that receives an energizing signal from a remote devicevia the second antenna and converts the energizing signal from RFelectrical energy to DC electrical energy that energizes the passivetracking device. The passive tracking device further includes atransmission module that modulates a response signal for transmission inthe first frequency band and outputs the modulated response signal tothe first antenna for transmission in accordance with a communicationprotocol. The response signal includes a message indicating a deviceidentifier of the passive tracking device. The transmission moduleincludes a bulk acoustic wave reference oscillator that produces anoutput frequency, the bulk acoustic wave reference oscillator includinga bulk acoustic wave delay reference. The transmission module modulatesthe response signal such that the response signal has a carrierfrequency based on the output frequency of the bulk acoustic wavereference oscillator.

In embodiments, the bulk acoustic wave reference oscillator includes amaster clock, a time difference detector, a phase frequency detectionmodule, and a loop filter. In some embodiments, the master clock outputsthe output frequency to other components of the first transmissionmodule for use as a carrier frequency reference and outputs the outputfrequency to the time difference detector. In some embodiments, the timedifference detector detects a plurality of echoes of the bulk acousticwave delay reference, generates a first echo signal and a second echosignal based on a first echo and a second echo of the plurality ofechoes, respectively, compares the first echo signal to the outputfrequency to generate an end pulse, and outputs both the end pulse andthe second echo signal to the phase frequency detection module. In someembodiments, the phase frequency detection module compares a phase ofthe end pulse to a phase of the second echo signal, generates a pumppulse, and generates a current based on the pump pulse. In someembodiments, the loop filter amplifies the current and outputs theamplified current to the master clock, thereby forming a feedback loopand correcting the output frequency.

In some embodiments, the pump pulse is a pump-down pulse when the phaseof the end pulse is earlier than the phase of the second echo signal,and the phase frequency detection module generates negative currentbased on the pump-down pulse. In some of these embodiments, the pumppulse is a pump-up pulse when the phase of the end pulse is later thanthe phase of the second echo signal, and the phase frequency detectionmodule generates positive current based on the pump-up pulse. In someembodiments, the time difference detector includes a temperaturecompensation module that receives a temperature reading and outputs atemperature adjustment signal to the time difference detector based onthe temperature reading, and the time difference detector adjusts one orboth of the echo signals and the end pulse based on the temperatureadjustment signal.

In embodiments, the bulk acoustic wave delay reference is a first bulkacoustic wave delay reference and the plurality of echoes is a firstplurality of echoes. In some of these embodiments, the bulk acousticwave oscillator includes a bulk acoustic wave temperature sensor. Thebulk acoustic wave temperature sensor detects a second plurality ofechoes of the bulk acoustic wave delay reference, generates a first echosignal and a second echo signal based on a first echo and a second echoof the second plurality of echoes, generates a coarse temperaturereading based on the first and second echo signals based on the firstecho and the second echo of the second plurality of echoes,respectively, and outputs the coarse temperature reading to the timedifference detector of the bulk acoustic wave oscillator. In someembodiments, the bulk acoustic wave temperature sensor receives theoutput frequency from the bulk acoustic wave generator and generates aprecise temperature reading based on the fifth and sixth echo signalsand the output frequency. In some embodiments, the passive trackingdevice further includes a bulk acoustic wave temperature sensor thatgenerates one or both of a coarse temperature reading and a precisetemperature reading, the bulk acoustic wave temperature sensor includinga second bulk acoustic wave delay reference.

In embodiments, the bulk acoustic wave temperature sensor detects asecond plurality of echoes of the second bulk acoustic wave delayreference, generates a first echo signal and a second echo signal basedon a first echo and a second echo of the second plurality of echoes,respectively, generates the coarse temperature reading based on thefirst and second echo signals based on the first echo and the secondecho of the second plurality of echoes, and outputs the coarsetemperature reading to the bulk acoustic wave oscillator. In some ofthese embodiments, the bulk acoustic wave temperature sensor receivesthe output frequency from the bulk acoustic wave generator and generatesthe precise temperature reading based on both the output frequency andthe first and second echo signals based on the first echo and the secondecho of the second plurality of echoes. In some embodiments, the bulkacoustic wave temperature sensor outputs the precise temperature readingto the transmission module for inclusion in the response signal.

In embodiments, the passive tracking device further includes a bulkacoustic wave transformer that transforms energizing signals receivedvia the second antenna, the bulk acoustic wave transformer including asecond bulk acoustic wave delay reference. In some of these embodiments,the bulk acoustic wave transformer increases an impedance of theenergizing signals.

In embodiments, the transmission module modulates the response signalsuch that the response signal has a carrier frequency substantiallyequal to a factor of the output frequency of the bulk acoustic wavereference oscillator.

In embodiments, the transmission module is a first transmission module,the response signals are first response signals, the energizing signalsare first energizing signals, the communication protocol is a firstcommunication protocol, the message is a first message, and the deviceidentifier is a first device identifier. In some of these embodiments,the passive tracking device further includes a third antenna that bothtransmits second response signals and receives second energizing signalsin a third frequency band. The passive tracking device also includes asecond transmission module that prepares a second response signal fortransmission in the third frequency band and facilitates transmission ofthe prepared second response signals by toggling impedance of the thirdantenna when the passive tracking device operates in a second mode inaccordance with a second communication protocol, and wherein the secondresponse signal includes a second message indicating a second deviceidentifier of the passive tracking device. The passive tracking devicefurther includes a mode selection module that determines whether thepassive tracking device is to operate in the first mode or the secondmode based on a received energizing signal from a remote device via thesecond antenna and/or the third antenna. In some of these embodiments,the first frequency band is equal to the second frequency band.

According to some embodiments of the present disclosure, an aggregatordevice of an intelligent tracking system is disclosed. The aggregatordevice may include one or more storage devices; one or more longdistance communication units that communicate with external devicesusing one or more long distance communication protocols; at least oneshort distance communication units that communicate with proximatedevices using one or more short range communication protocols; a GPSdevice; and one or more processors that execute executable instructions.The instruction cause the processing device to: broadcast, via the shortdistance communication unit, energizing signals to tracking devices in aread range of the aggregator device, wherein the energizing signalstrigger the tracking devices to broadcast tracking messages; receive oneor more response signals from one or more respective responding trackingdevices via the short distance communication unit, wherein each responsesignal includes a tracking messages from a respective respondingtracking device that includes tracking information; generate a trackingrecord based on a respective response signal; and report the trackingrecord to a backend server system.

In embodiments, the one or more short distance communication unitsinclude a multiple-output-multiple-input (MOMI) communication devicethat is configured to receive a response signal from a respondingtracking device and to determine a range and bearing of the respondingtracking device with respect to aggregator device based on the responsesignal. In some of these embodiments, the MOMI communication deviceincludes at least one MOMI transceiver that comprises: a first radiofrequency (RF) antenna; and a second RF antenna that is in closeproximity to the first RF antenna and is set at an angle that is greaterthan zero degrees and less than 180 degrees from the first RF antenna.In some of these embodiments, the MOMI device is configured to: receivean energizing command from the one or more processors; modulate anenergizing signal between the first RF antenna and the second RF antennato the tracking devices in the read range of the aggregator device;receive a first response signal at the first RF antenna and a secondresponse signal at the second RF antenna from the responding trackingdevice; determine the range and bearing of the responding trackingdevice based on a first signal strength of the first response signal anda second signal strength of the second response signal; and outputtingthe range and bearing to the processing device.

In embodiments, the aggregator device further includes a set of one ormore environmental sensors that respectively output sensor data. In someof these embodiments, the executable instructions further cause the oneor more processors to: receive the sensor data; classify an existence ofan environmental incident based on the sensor data and a machine learnedmodel; and in response to classifying the environmental incident:generate an environmental incident record; and report the environmentalincident to the backend server system.

In embodiments, the executable instructions further cause the one ormore processors to receive a camera signal. In some of theseembodiments, the executable instructions further cause the one or moreprocessors to classify a trackable item in one or more frames in thecamera signal using an image classifier trained to identify trackableitems. In some of these embodiments, the executable instructions furthercause the one or more processors to determine that a tracking device ismissing, damaged, or otherwise unreadable in response to classifying atrackable item and not receiving a tracking message corresponding to thetrackable item. In some embodiments, the executable instructions furthercause the one or more processors to classify visual indicia affixed to atrackable item in one or more frames in the camera signal using an imageclassifier trained to identify trackable items and visual indicia. Insome of these embodiments, the executable instructions further cause theone or more processors to: scan the visual indicia; and decode thevisual indicia to obtain a value, the value being indicative of trackinginformation of the item to which the visual indicia are affixed. In someof these embodiments, the executable instructions further cause the oneor more processors to determine that a tracking device is missing,damaged, or otherwise unreadable in response to not receiving a trackingmessage that corresponds to the value decoded from the visual indicia.

In some embodiments, the aggregator device further includes a camerathat outputs the camera signal. In some embodiments, the one or moreprocessors receive the video signal from a remote video camera via thelong distance communication unit or the short distance communicationunit or via a connector cable. In some embodiments, the video signal isa 3D video signal that includes high resolution color video and depthvideo. In some embodiments, the executable instructions further causethe one or more processors to: receive first range and bearing dataderived from a first response signal from a first tracking device;determine first tracking data corresponding to the first tracking devicebased on the first response signal; receive second range and bearingdata derived from a second response signal from a second trackingdevice; determine second tracking data corresponding to the secondtracking device based on the second response signal; classify a firsttrackable item and a second trackable items in one or more frames in thecamera signal using an image classifier trained to identify trackableitems; and disambiguate the first trackable item and the secondtrackable item based on the first range and bearing data and the secondrange and bearing data, such that the first tracking data is associatedwith the first trackable item and the second tracking data is associatedwith the second trackable item based on the disambiguation.

In embodiments, the responding tracking devices include passive trackingdevices. In some of these embodiments, the passive tracking devicesinclude multi-medium tracking devices that are configured with an RFIDtag and a BLE transmitter, such that the multi-medium tracking devicesmay be read via RFID interrogators or BLE scanners. In some of theseembodiments, the RFID tag and the BLE transmitter are integrated into asingle ASIC.

According to some embodiments of the present disclosure, an intelligenttracking system is disclosed. The intelligent tracking system includesone or more passive tracking devices, an exciter, and a tracker. Eachpassive tracking device includes one or more transceivers and isenergized by an electromagnetic frequency. In response to beingenergized each passive tracking device transmits a short message. Theexciter emits the electromagnetic frequency to power the passive tag.The tracker receives short messages from the one or more passivetracking devices and confirms the presence of the one or more passivetracking devices in a vicinity of the tracker based on the receivedmessages.

In embodiments, the short messages are Bluetooth Low Energy (BLE)beacons. In some of these embodiments, each of the BLE beacons includesa respective device identifier of a respective passive tracking deviceof the one or more passive tracking devices that transmitted the BLEbeacon. In embodiments, each of the short messages includes a respectivedevice identifier of a respective passive tracking device of the one ormore passive tracking devices that transmitted the short message. Insome of these embodiments, the respective passive tracking deviceencrypts the respective device identifier in the short message using alow power encryption algorithm. In some of these embodiments, therespective passive tracking device encrypts the respective deviceidentifier in the short message based on a shared secret key and ashared secret pattern. The shared secret pattern may define a pattern atwhich random bits are inserted into the short message prior toencryption with the shared secret key. Furthermore, in embodiments, theintelligent tracking system includes an authenticating device thatauthenticates the respective passing device using the shared secretpattern and the shared secret key. In some of these embodiments, theauthenticating device is the tracker. In other embodiments, theauthenticating device is a backend server system in communication withthe tracker.

In embodiments, the exciter is embedded in the tracker. In otherembodiments, the exciter is a stand-alone device. In some embodiments,the intelligent tracking system includes a backend server system thatmaintains locations of the one or more passive tracking devices. In someof these embodiments, the backend server system manages an inventory ofitems via the locations of the one or more passive tracking devices.

In embodiments, the one or more passive tracking devices each include atemperature sensor that outputs a current temperature upon beingenergized, wherein each passive tracking device includes the currenttemperature data in the short message output by the passive trackingdevice. In some embodiments, the intelligent tracking system includes abackend server system that maintains a temperature log based on thecurrent temperature data in the respective short messages transmitted bythe passive tracking devices and time stamps associated with thetemperature data. In embodiments, the intelligent tracking systemincludes a backend server system that receives the motion data anddetermines a motion profile corresponding to an item associated with aparticular passive tracking device based on the motion data. Inembodiments, the one or more passive tracking devices each include alight sensor that outputs a value indicating a detection of ambientlight in a vicinity of the passive tracking device, wherein the value isincluded in the short message upon the passive tracking device beingenergized. In embodiments, the one or more passive tracking devices eachinclude a motion sensor that outputs motion data that indicates arespective motion of the passive tracking device, wherein the motiondata is included in the short message upon the passive tracking devicebeing energized. In some embodiments, the intelligent tracking systemincludes an augmented reality enabled device that is configured todisplay an indicia of a passive tracking device when the augmentedreality enabled device is oriented in a direction of the passivetracking device.

In embodiments, the one or more passive tracking devices include amulti-band antenna such that each passive tracking device receives theelectromagnetic frequency at a first frequency and transmits the shortmessages at a second frequency. In embodiments, the exciter includes amulti-band antenna such that the exciter transmits the electromagneticfrequency at a first frequency and receives short messages at a secondfrequency.

In embodiments, the tracker is a user device configured to communicatewith the one or more passive tracking devices.

In embodiments, the intelligent tracking system includes a backendserver system that receives location data corresponding to the one ormore passive tracking devices from the tracker and generates a virtualmap of an area corresponding to the one or more passive tracking devicesbased on the location data.

In embodiments, the tracker is configured to determine acharacterization of an environment of the tracker; and to determine aform of communication with which the tracker communicates with a backendserver based on the characterization, wherein the tracker is configuredto select from more than one different forms of communication.

In embodiments, each of the one or more passive tracking devicesincludes a plurality of antennas and is configured to: transmit anadvertising packet to the tracker in response to being energized usingone of the plurality of antennas, wherein the advertising packetindicates the antenna being used; receive a response packet from thetracker in response to the advertising packet, the response packetincluding a received signal strength indication that indicates astrength of a signal containing the advertising packet; and selectivelytransmit the short message to the tracker using the one of the pluralityof antennas based on the received signal strength indication.

In embodiments, each passive tracking device of the one or more passivetracking devices is fabricated with an electrostatic dischargeprotection mechanism at a connection between an antenna of the passivetracking device and a silicon chip of the passive tracking device. Insome of these embodiments, the electrostatic discharge protection isremoved after the silicon chip is inlaid into a housing of the passivetracking device.

In embodiments, each passive tracking device of the one or more passivetracking devices includes a MEMS oscillator.

In some embodiments, the passive tracking devices include multi-mediumtracking devices that are configured with an RFID tag and a BLEtransmitter, such that the multi-medium tracking devices may be read viaRFID interrogators or BLE scanners. In some of these embodiments, theRFID tag and the BLE transmitter are integrated into a single ASIC

A more complete understanding of the disclosure will be appreciated fromthe description and accompanying drawings and the claims, which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a betterunderstanding of the disclosure, illustrate embodiment(s) of thedisclosure and together with the description serve to explain theprinciple of the disclosure. In the drawings:

FIG. 1 is a schematic illustrating an example intelligent trackingsystem, including a tracking system and a backend server system.

FIG. 2 is a schematic illustrating an example lifecycle of a productaccording to some embodiments of the present disclosure.

FIG. 3 is a schematic illustrating an example configuration of a passivetracking device according to some embodiments of the present disclosure.

FIG. 4 is a schematic illustrating an example configuration of a passivetracking device according to some embodiments of the present disclosure.

FIG. 5 is a flowchart depicting an example set of operations of a methodfor determining whether the passive tracking device is to operate in thefirst mode or the second mode according to some embodiments of thepresent disclosure.

FIG. 6 is a flowchart depicting examples operations of a method 600 foroperating a passive tracking device 108 according to some embodiments ofthe present disclosure.

FIG. 7 is a flowchart depicting examples operations of a method forauthenticating a tracking device according to some embodiments of thepresent disclosure.

FIG. 8 is a flowchart depicting examples operations of a method forgenerating an encrypted message used to authenticate a tracking deviceaccording to some embodiments of the present disclosure.

FIG. 9 is a flowchart depicting examples operations of a method forauthenticating a tracking device based on a received encrypted transmitmessage according to some embodiments of the present disclosure.

FIG. 10 is a schematic illustrating an example bulk acoustic waveoscillator according to some embodiments of the present disclosure.

FIG. 11 is a schematic illustrating an example configuration of a masterclock of a bulk acoustic wave oscillator according to some embodimentsof the present disclosure.

FIG. 12 is a schematic illustrating an example configuration of a timedifference detector of a bulk acoustic wave oscillator according to someembodiments of the present disclosure.

FIG. 13 is a schematic illustrating example configurations of a phasefrequency detector and loop filter of a bulk acoustic wave oscillatoraccording to some embodiments of the present disclosure.

FIG. 14 is a schematic illustrating an example configuration of a bulkacoustic wave oscillator according to some embodiments of the presentdisclosure.

FIG. 15 is a schematic illustrating an example configuration of a bulkacoustic wave oscillator according to some embodiments of the presentdisclosure.

FIG. 16 is a schematic illustrating an example configuration of a bulkacoustic wave oscillator according to some embodiments of the presentdisclosure.

FIG. 17 is a schematic illustrating an example configuration of a bulkacoustic wave oscillator according to some embodiments of the presentdisclosure.

FIG. 18 is a schematic illustrating an example configuration of apassive tracking device according to some embodiments of the presentdisclosure.

FIG. 19 is a schematic illustrating an example set of components of anaggregator device according to some embodiments of the presentdisclosure.

FIG. 20 is a schematic illustrating an examplemultiple-output-multiple-input device according to some embodiments ofthe present disclosure.

DETAILED DESCRIPTION

FIG. 1 illustrates an intelligent tracking system 10. An intelligenttracking system 10 (or “system 10”) may include one or more trackingdevice systems 100 (or “tracking systems 100”) and a backend serversystem 120. In embodiments, the intelligent tracking system 10 mayfurther include user devices 130 and/or augmented reality (AR)-enableduser devices 140. The system 10 may include additional components notshown.

A tracking system 100 may include one or more tracking devices. Inembodiments, the tracking system 100 includes any combination of one ormore multi-mode tracking devices 102, one or more aggregator device 104,one or more paired tracking devices 106, one or more passive trackingdevices 108, one or more exciters 110, one or more dual-medium trackingdevices 112, one or more visual indicia trackers 114, and one or morevision systems 116.

In embodiments, a multi-mode tracking device 102 is an electronic devicethat is configured to determine its geolocation and to report itsgeolocation to the backend server system 120 via a communicationnetwork. The multi-mode tracking device 102 may be configured tocommunicate with the server system 120 using long-distance communication(e.g., directly via the communication network (e.g., using a cellularconnection)), or using short-distance communication (e.g., through anintermediate device in the tracking system 100 (e.g., the aggregatordevice 104)). For example, in some scenarios a multi-mode trackingdevice 102 may be in an environment that prohibits the multi-modetracking device 102 from connecting to a cellular network or may be setto a mode where the multi-mode tracking device 102 is precluded fromcommunicating via the cellular network. In these scenarios, themulti-mode tracking device 102 may transmit its location data to anaggregator device 104, which may transmit the location data to thebackend server system 120. In embodiments, the multi-mode trackingdevice 102 may be also configured to determine other types of data thatmay be reported in addition to or in lieu of the location data. Themulti-mode tracking device 102 may include one or more environmentalsensors that collect data corresponding to the multi-mode trackingdevice 102 or an environment thereof. For example, the multi-modetracking device 102 may determine and/or report temperature dataindicating an ambient temperature in the environment of the multi-modetracking device 102, motion data describing motion of the multi-modetracking device 102, humidity data indicating a humidity of theenvironment of the multi-mode tracking device 102, light data indicatinga degree of ambient light sensed in the environment of the multi-modetracking device 102, and the like. In embodiments, the multi-modetracking device 102 may periodically log the collected data, such thatthe multi-mode tracking device 102 may track the conditions of an itembeing shipped or stored in a log. For example, a multi-mode trackingdevice 102 may maintain a temperature log that defines the temperatureof an environment proximate to the device over a period of time. Thesetypes of logs may be required when transporting items such aspharmaceuticals, chemicals, and food. In some embodiments, a multi-modetracking device 102 may maintain a temperature log (or other data logs)on behalf of other devices that do not have sufficient processing orstorage capabilities to keep such logs.

A multi-mode tracking device 102 may include a rechargeable battery(e.g., a 3.7V 6800 mAh lithium ion battery), such that it may be placedin an environment (e.g., a truck, warehouse, shipping container, and thelike) where the multi-mode tracking device 102 may be moved and notconnected to power for weeks or months.

An aggregator device 104 is an electronic device that is configured toaggregate location data from one or more devices in the tracking system100 (e.g., multi-mode tracking devices 102, paired tracking devices 106,and/or passive tracking devices 108) and to report the location data tothe backend server system 120. In embodiments, an aggregator device 104is configured to authenticate various devices in the tracking system100. In this way, counter-fitting of devices of a tracking system 100may be averted.

In embodiments, an aggregator device 104 is a mobile aggregator device104. A mobile aggregator device 104 may be an aggregator device 104 thatis configured for portability. A mobile aggregator device 104 mayinclude a rechargeable battery (e.g., a 3.7V 6800 mAh lithium ionbattery), such that it may be placed in an environment where theaggregator device 104 may be moved and not connected to power for weeksor months.

In embodiments, an aggregator device 104 may be a fixed aggregatordevice. A fixed aggregator device may be an aggregator device 104 thatis configured to be at a fixed location. A fixed aggregator device maybe connected to a power source (e.g., an AC outlet). A fixed aggregatordevice may further be configured to perform more power intensiveoperations, such as determining locations of other devices of a trackingsystem, performing power intensive encryption operations, and the like.

In some embodiments, an aggregator device 104 may maintain data logs(e.g., temperature logs, humidity logs, and the like) on behalf of otherdevices (e.g., passive tracking devices 108) that do not have sufficientprocessing or storage capabilities to keep such logs. In this way, theaggregator device 104 may maintain a separate log for each passivetracking device 108. Each respective log may correspond to a respectivepassive tracking device 108 and may include a device identifier of therespective passive tracking device 108, a time stamp of each respectivedata item collected from the passive tracking device 108, and the dataitem corresponding to the time stamp.

In some embodiments, a multi-mode tracking device 102 may be set tofunction as an aggregator device 104. In embodiments, an aggregatordevice 104 may be configured to include an exciter device 110 (discussedfurther below).

A paired tracking device 106 may be an electronic device configured todetermine its geolocation and report its geolocation to the backendserver system via an aggregator device 104. A paired tracking device 106may utilize a short-distance communication protocol to communicate withthe aggregator device. In embodiments, the paired tracking device 106may implement the Bluetooth™ or Bluetooth Low Energy™ communicationprotocol to communicate with an aggregator device 104. The pairedtracking device 106 may include one or more environmental sensors thatcollect data regarding the paired tracking device 106 or an environmentthereof, which the paired tracking device 106 may monitor to report thecollected sensor data to the aggregator device 104. For example, thepaired tracking device 106 may determine and/or report temperature dataindicating an ambient temperature in the environment of the pairedtracking device 106, motion data describing motion of the pairedtracking device 106, humidity data indicating a humidity of theenvironment of the paired tracking device 106, light data indicating adegree of ambient light sensed in the environment of the paired trackingdevice 106, and the like. In embodiments, the paired tracking device 106may periodically log the collected data, such that the paired trackingdevice 106 may track the conditions of an object being shipped or storedin a log (e.g., a temperature log).

A paired tracking device 106 may include a rechargeable battery (e.g., a3.0V 6800 mAh lithium ion battery), such that it may be placed in anenvironment (e.g., a truck, warehouse, shipping container, and the like)where the paired tracking device 106 may be moved and not connected topower for weeks or months.

A passive tracking device 108 is a small low-cost electronic device thatcommunicates with another device in the tracking system 100. Unlike thepaired tracking devices 106 or the multi-mode tracking devices 102, thepassive tracking device 108 does not include an onboard long-term powerstorage mechanism (e.g., no battery). Rather, the passive trackingdevice 108 is configured to be energized by an electromagnetic field(e.g., a radio frequency (RF) signal. This allows the passive trackingdevice 108 to be a small and relatively low cost tracking solution. Itis noted that the passive tracking devices 108 may include short-termpower storage mechanisms, such as capacitors to store a charge for ashort duration that is obtained via energization. As will be discussedbelow, the tracking system 100 may include one or more exciters 110 thatare configured to emit electromagnetic signals that energize the passivetracking devices 108. The exciters 110 may be stand-alone devices or maybe integrated into another device of the tracking system 100 (e.g., inan aggregator 104 or multi-mode tracking device 102). A more detaileddiscussion on the use of RF-related technology may be found in U.S. Pat.No. 8,774,329 to Kawaguchi, the contents of which are hereinincorporated by reference.

Referring back to FIG. 1, in embodiments, the passive tracking device108 may include a small integrated circuit (e.g., <2 mm×2 mm) that maybe integrated into a small form factor. For example, the passivetracking device 108 may be integrated into a label or tile less than 1cm×1 cm in area. In this way, the passive tracking device 108 may beadhered to a package being shipped, inserted into a box of valuablegoods (e.g., medical supplies), embedded in a clothing item (e.g., ashoe), or used in any other suitable scenario.

A passive tracking device 108 may communicate short messages to anotherdevice (e.g., aggregator device 104) that includes a device identifier(“device ID”) that identifies the passive tracking device 108 from otherpassive tracking devices 108. By transmitting the short message, apassive tracking device 108 may confirm its presence in the proximity ofthe aggregator device 104. In embodiments, the passive tracking devices108 include a Bluetooth™-enabled transceiver configured in accordancewith the Bluetooth communication protocol(s). In embodiments, thepassive tracking devices 108 may communicate with other devices (e.g.,an aggregator device 108) having a Bluetooth-enabled transceiver. Inembodiments, the Bluetooth-enabled transceiver utilizes the BluetoothLow Energy (BLE) protocol (e.g., BLE-enabled transceivers). BLE isshort-distance communication protocol developed by Bluetooth SIG thatrequires less power consumption than other Bluetooth communicationprotocols. In embodiments, the passive tracking devices 108 areconfigured to transmit beacons upon being energized. A beacon may be oneor more data packets of fixed length that are encoded according to acommunication protocol (e.g., Bluetooth™ or BLE). Beacons arenon-limiting examples of short messages. In embodiments, the beacon mayindicate a device identifier (ID) of the passive tracking device 108transmitting the short message (e.g., beacon). A passive tracking device108 may include additional data in the short message (e.g., beacon),including but not limited to, temperature data, motion data, and/orambient light data. It is noted that an upstream tracker (e.g., anaggregator 104, multi-mode tracking device, or user device 120) or thebackend server system 120 may apply a time stamp to the temperaturedata, motion data, and/or ambient light data received from a passivetracking device 108, as the passive tracking device 108 transmits theshort message in close temporal proximity to when the passive trackingdevice 108 samples this data.

The passive tracking devices 108 may each include one or more antennasthat are used to receive and transmit electromagnetic signals. In thisway, an antenna may receive an electromagnetic signal to energize thepassive tracking device 108 and/or may transmit an electromagneticsignal via a short-distance communication link (e.g., BLE) to anotherdevice of the tracking system 100. The passive tracking device 108 maytransmit in very short distances (e.g., <2 m). In some embodiments, thepassive tracking device 108 may be configured to transmit in longerdistances (e.g., ˜10 m) if sufficiently energized by another device. Asmentioned, the passive tracking device 108 may be energized uponreceiving an electromagnetic signal via the antenna. In embodiments, theantenna may be metallic paint or material that is applied to an outerhousing of the passive tracking device 108. In these embodiments, theantenna may be painted to cover the entire housing, so as to improve thereception of the passive tracking device 108.

In embodiments, the passive tracking devices 108 may be configured withdual band antennas. For example, a passive tracking device 108 mayinclude a dual band antenna that allows efficient energy harvesting at900 MHz or 2.4 GHz and that transmits beacons at 2.4 GHz. Inembodiments, the passive tracking devices 108 may be configured withmulti-band antennas. For example, a passive tracking device 108 may beconfigured with a multi-band antenna that allows efficient energyharvesting from user device 130 (e.g., smartphones or tablets) signalsat 700, 850, 1900 MHz as well as 900 and 2.4 GHz ISM band signals.

One issue that may arise with BLE-enabled transceivers in a passivetracking device 108 is that BLE-enabled transmitters can be implementedwith a very simple RF and digital design, but receivers are much morecomplex to implement. Simple “transmit-only” passive BLE tacking devicescan be significantly enhanced by a limited ability to securely receiveand write data in a tag. The limitations may include only specializeddevices with very close range and consistent high signal levels. The BLEprotocol in the Bluetooth 5.0 specification requires data to be sentfrom master to slave devices using a connection event. This may requirethe passive tracking devices 108 to implement a more complex statemachine and receiver than desired given the power and processingconstraints of the passive tracking devices 108.

Thus, in some embodiments, the tracking system 100 may implement aproprietary version of BLE advertising packets to transmit both RF powerand data from a powered device (e.g., an exciter 110) to a passivetracking device 108. Traditionally, a BLE advertising packet is a packetthat may be transmitted by a BLE peripheral device to anotherBLE-enabled device (or Bluetooth-enabled device) to announce theperipheral device's presence to the other BLE-enabled device. Inembodiments, a command structure can be embedded into the advertisingdata field. In some of these embodiments, the commands may include, butare not limited to: (i) Write mode (e.g., a very short and uniquecommand to tell the passive tracking device 108 to listen; (ii)Authenticate Sender; (iii) Write Address and Data; (iv) RequestAcknowledgement of Write Address and Status; and (v) Send Beacon WithAcknowledgement (by passive tracking device 108).

In some embodiments, writing data to the tag can be accomplished with anamplitude-shift keying (ASK) modulation scheme on a constant wave toreduce the complexity of the receiver. In these embodiments, the passivetracking device 108 may include a UHF RFID reader if the passivetracking device 108 implements, for example, a basic C1G2 (Class-1,Generation-2) interface section and has a multi-band antenna.Additionally or alternatively, the passive tracking device 108 maycombine a near field communication (NFC) tag and a passive BLE module.

Passive tracking devices 108 may communicate with a number of differenttypes of devices. In embodiments, the passive tracking device 108 maycommunicate with an aggregator device 104, a multi-mode tracking device102, an exciter 110, a user device 130, AR-enabled user device 140,and/or a reader device 150. In embodiments, the passive tracking devices108 are configured to transmit beacons upon being energized. Asmentioned, the beacon may indicate a device identifier (ID) of thepassive tracking device 108 transmitting the beacon. In this way, thepassive tracking device 108 announces its proximity to another device inthe tracking system 100 each time the passive tracking device 108 isenergized. In response to a beacon, the device receiving the beacon fromthe passive tracking device 108 may read the device ID of the device andmay log the presence of the passive tracking device, as well as anyother data transmitted in the beacon.

In embodiments, the passive tracking device 108 may encrypt the deviceID, such that counterfeiting of passive tracking devices may beprevented. This may be very important in inventory management systems ortracking applications in general. For example, a malicious actor may tryto counterfeit a passive tracking device in order to steal a packagehaving an authentic passive tracking device 108 affixed thereon. Inembodiments, the passive tracking devices 108 may implement a low powerencryption algorithm to encrypt the device ID (or any other data thatneeds encryption). In embodiments, the passive tracking device 108 mayutilize a shared secret key and a shared secret pattern to encrypt thedevice ID. The shared secret key may be a numeric value that is used toencrypt the device ID. The shared secret key may be stored on arespective passive tracking device and may be used to encrypt a message(e.g., a string of bits) to be encrypted. The authenticating device(e.g., an aggregator device 104, a backend server system 120, a userdevice 130, or an exciter 110) also knows the shared secret key and theshared secret pattern. The shared secret pattern defines a pattern inwhich bits are inserted into the message to be encrypted. For example,in a message containing up to 8 bytes, an example pattern may indicatethat a bit is to be inserted between the first bit and a second bit,between the fifth and sixth bit, between the sixteenth and theseventeenth bit, between the 30^(th) and 3^(st) bit, between the 42^(nd)and 43^(rd) bit, and between the 50^(th) and 51^(st) bit. The passivetracking device may generate a random N-bit string (e.g., five bits inthe example above), and may insert the respective bits from the N-bitstring into the message to be encrypted in accordance with the secretpattern. The passive tracking device may then encrypt the message,having the N-bits inserted therein, using the shared secret key and maytransmit the encrypted message. By utilizing a different random N-bitstring to insert into the message to be encrypted (e.g., the device ID)at each iterative transmission, the encrypted message is ensured to varybetween transmissions despite containing the same device ID and beingencrypted by the same secret key. An authenticating device may receivethe encrypted message and may decrypt the encrypted message using theshared secret key. The authenticating device may also remove bits fromthe decrypted message in accordance with the shared secret pattern toobtain the original message (e.g., remove the second bit, the seventhbit, the 18^(th) bit, the 34^(th) bit, the 47^(th) bit, and the 56^(th)bit). Upon authenticating a passive tracking device 108, theauthenticating device or a device associated therewith, may confirm thepresence of the passive tracking device in a general location.

In embodiments, the passive tracking device 108 may include one or moreintegrated sensors that allow the passive tracking device 108 to collectadditional types of data. In embodiments, the passive tracking device108 may include a temperature sensor. The temperature sensor may be athermistor included in the integrated circuit that is used for otherfunctions of the integrated circuit. In this way, the passive trackingdevice 108 may piggy-back a temperature reading from the temperaturesensor without adding any additional sensors to the passive trackingdevice 108. Upon reading the temperature data from the temperaturesensor, the passive tracking device 108 may include the temperature datain a beacon to be transmitted, thereby providing the instantaneous orcurrent temperature of the environment of the passive tracking device108. As the passive tracking devices 108 are not powered and have littleor no storage capabilities, the passive tracking devices 108 may only beable to provide current temperature data. Another device (e.g., theaggregator device 104 or the backend server system 120) may receive thetemperature data from a collection of passive tracking devices 108, mayapply a time stamp to the temperature data, and/or may maintain atemperature log for each respective passive tracking device 108. In thisway, items that are being shipped where a temperature log must bemaintained can be tracked using the passive tracking devices 108. Inthese embodiments, a logging device (an aggregator device 104 having anintegrated exciter 110) or combination of devices (e.g., an aggregatordevice 104 and an exciter 110) may periodically energize the passivetracking devices 108 in the vicinity thereof to obtain the temperaturedata from each respective passive tracking device 108 and may log thetemperature data obtained therefrom in a temperature log, as discussedabove. It is noted that in some embodiments, certain passive trackingtags may be configured as “passive temperature tracking tags.” In theseembodiments, passive temperature tracking tags can be included insidepackages to measure the temperature of an item (e.g., a food item)inside the package. The passive temperature tracking tags may allow thesystem to track ambient temperatures inside the package, so that thetemperatures inside and outside of the package may be compared.

In embodiments, a passive tracking device 108 may include a lightsensor. In some of these embodiments, the light sensor is aphoto-detector. A photo detector may output a first signal if thephoto-detector has been exposed to a sufficient amount of light and asecond signal if the photo-detector has not been exposed to a sufficientamount of light. Upon being energized, the passive tracking device 108may include light data indicating whether the passive tracking device108 has been exposed to light in a beacon that is transmitted to anaggregator device 108. In some embodiments, the photo-detector mayfurther be configured to energize the passive tracking device 108 uponbeing exposed to light. In these embodiments, a passive tracking device108 may transmit a beacon containing light data indicating the presenceof light, upon the passive tracking device 108 being energized. In thisway, the aggregator device 104 may determine whether a particularpackage or item has been opened. In embodiments, a visible or infra-redlaser can be pointed at the one of a passive tracking devices 108. Apassive tracking device 108 that is being illuminated by the visible orinfra-red may be triggered to output a beacon where the light data inthe beacon indicates that the passive tracking device 108 wasilluminated.

In embodiments, the passive tracking devices 108 may be configured toinclude one or more motion sensors. For example, a passive trackingdevice 108 may include an accelerometer (e.g., a MEMS accelerometer). Inthese embodiments, an accelerometer may be integrated into the passivetracking devices 108 to enable identifying passive tracking devices thatare in motion. The accelerometer may output a signal indicating amagnitude of the movement of the passive tracking device in anydirection. This information can be used to determine if the passivetracking device 108 is moving at a walking acceleration, a drivingacceleration, a plane acceleration, and the like. In embodiments, apassive tracking device 108 may be configured to transmit beacons moreoften, less often, or not at all when it the passive tracking device isdetermined to be in motion.

In embodiments, the passive tracking devices 108 may transmit beacons touser devices 120 and/or AR-enabled devices 130. A user device 120 may beany suitable electronic device that has a user interface. For example, auser device 120 may be a smart phone, a tablet computing device, agaming device, a scanner, and the like. An AR-enabled device 130 may bea device that is configured to display computer generated overlays ontoa screen. Examples of AR-enabled devices include smart phones, tabletcomputing devices, smart-glasses (e.g., Google Glass®), video gamedevices, and the like.

In embodiments, the passive tracking devices 108 include one or moreoscillators to enable transmission of an electromagnetic signal. Incertain scenarios, BLE requires accurate carrier frequency to transmit abeacon. Crystals are very accurate, but are typically in very largepackages. As such, in some embodiments, the oscillators of the passivetracking devices 108 are MEMS oscillators that use tiny resonators thatare bonded to a single silicon chip. This enables lowest cost and sizesolution for a fully integrated passive tracking device. While MEMSoscillators have limitations (e.g., longer turn on time, high phasenoise, die mounting directly on silicon, tuning calibration, etc.), thepassive tracking devices 108 may be configured to schedule turn on timefor the oscillator at lower energy storage levels than the maincircuitry. In some embodiments, the crystal oscillator silicon die areintegrated into the same package as the silicon chip of a passivetracking device 108.

An issue that may arise from using available silicon technology in apassive tracking device 108 is that RF-voltage levels of 100 mV or moreare desirable at the inputs of voltage rectifying circuits for energyharvesting. These types of circuits begin to follow a square-lawbehavior at these voltages, which means a harvesting efficiency whichscales with input voltage. In order to obtain desired voltages at lowerpower levels (e.g., <−20 dbM), a higher parallel equivalent inputresistance may be required. The Q of the resulting circuit may consistof the impedance of this parallel resistance in relation to theimpedance of the parallel input impedance of the circuit. In order tobuild usable passive tracking devices 108, it is desired that the inputQ of the circuit not become too high. Therefore, it is desirable toreduce the input capacitance to as low a value as possible. One of thelarge contributions to input capacitance is the electrostatic discharge(ESD) structure that is generally used on the antenna inputs to protectdevices during manufacture and handling. Thus, to reduce the inputcapacitance, ESD protection may be applied in a manner that can beremoved after the device is mounted into its form factor. For example,ESD protection may be removed after the silicon chip of the passivetracking device 108 is attached to the inlay of the passive trackingdevice (e.g., a plastic sheet with a metallic coating that acts as theantenna). It is assumed that in the inlay, the antenna terminals may beshorted with a DC path so that ESD protection is no longer necessary.Initially, during fabrication, handling, and testing, the ESD devicesare connected to the antenna input by one or more links. In embodiments,the links may be circuit connections that are made inside the siliconchip of the passive tracking device. The links may be metallic tracesformed in the silicon substrate during the fabrication process. Afterthe antenna circuit is attached, and a DC path is established betweenthe antenna circuit and the silicon chip, the one or more links can beremoved, thereby reducing the effective input capacitance and improvingperformance of the passive tracking device. The links can be removed inany suitable manner. For example, the links can be removed mechanically(e.g., physically cut), chemically (etched), or optically.

In embodiments, a passive tracking device 108 may be energized by anexciter 110. An exciter 110 may be a stand-alone device or may beintegrated into another device of the tracking system 100 (e.g., in amulti-mode tracking device 102 or an aggregator device 104). Inembodiments, the exciter 110 may broadcast an electromagnetic signal(e.g., an RF signal) that may energize any passive tracking devices 108in proximity to the tracking device 108. Furthermore, in someembodiments, an exciter 110 may be configured to receive beacons encodedin an electromagnetic signal from one or more passive tracking devices108 in proximity to the exciter 110. In embodiments, the exciter 110 maybe configured in a multi-band manner, whereby the exciter 110 maytransmit at electromagnetic signals at a first frequency (e.g., 900 MHz)and may receive electromagnetic signals at a second frequency (e.g., 2.4GHz).

One issue that arises is that passive tracking devices 108 are limitedin range by the minimum RF-level required to provide power to thedevice's chip. Once the passive tracking device 108 has sufficient powerto transmit a beacon, the range at which the beacon can be heard byother devices (e.g., exciters 110) is much farther. Thus, in someembodiments, supplemental exciters 110 to provide RF energy to passivetracking devices 108 may be placed in strategic locations, therebyenabling other devices (e.g., user devices 120, aggregator devices 104,and/or multi-mode tracking devices 102) to receive beacons from passivetracking devices 108 without having to power the passive trackingdevices themselves.

In embodiments, exciters 110 are placed in strategic locations andtransmit electromagnetic signals at a predefined duty cycle and up to apredefined power level. For example, in some embodiments, an exciter 110may be configured to transmit at a duty cycled 2.4 GHz energy sourcingsignal with transmit power up to 30 dBm and an antenna gain of up to 6dBi. In this way, the exciter 110 may be configured to increase theenergizing range in specific zones. In embodiments, the exciters 110 maybe one Watt, 900 MHz frequency hoppers. This may reduce or eliminate anyinterference concerns at 2.4 GHz and provide more power at a lowercarrier frequency with less path loss. In embodiments, the exciters 110may form a self-coordinated network via Ethernet, WiFi, and/orBluetooth. The FCC Part 15.247 which specifies maximum power and spreadspectrum requirements in ISM band may be found at:

-   -   https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol1/pdf/CFR-2013-title47-vol1-sec15-247.pdf,        the contents of which are herein incorporated by reference in        their entirety.

In embodiments, the exciters 110 may also implement 2.4 GHz receivers tolisten for BLE beacons from passive tracking devices 108 whiletransmitting energy at 900 MHz and building up an inventory in thecloud. In embodiments, the 2.4 GHz antennas in an exciter 110 mayinclude multiple antennas and radios for angle of arrival calculation.In these embodiments, the exciter 110 (or an aggregator 104 that mayinclude or be in communication with an exciter 110) may utilize thesignal strength at the different multiple antennas and/or radios todetermine an approximate location of a respective passive trackingdevice 108 based on the different signal strengths of the receivedsignal sensed at each antenna or radio and/or the angle of arrival ofthe received signal, as well as the known location of the exciter 110.In embodiments, the location, pointing orientation, exciter poweroutput, and the like of one or more exciters 110 may be calibrated witha single beacon device and/or an application running on a user device.In embodiments, the passive tracking devices 108 may be configured withdual band antennas. For example, a passive tracking device 108 mayinclude a dual band antenna that allows efficient energy harvesting at900 MHz or 2.4 GHz and that transmits beacons at 2.4 GHz. Inembodiments, the passive tracking devices 108 may be configured withmulti-band antennas (e.g., 700, 850, 1900 MHz as well as 900 and 2.4 GHzISM antennas). For example, the multi-band antennas may provide forefficient energy harvesting from user device (e.g., cell phone signals)at 700, 850, 1900 MHz as well as 900 and 2.4 GHz ISM band signals.

It is noted that in some embodiments, the supplemental transmission andbeacon reading functionality described with respect to the exciters110/aggregators 104 may be embedded in a smart home central device. Inthese embodiments, a user device application can access this data whenit comes in proximity to the supplemental transmitter.

A dual-medium passive tracking device 112 may be a type of passivetracking device 108 that supports two different communication methods.Thus, in embodiments, the dual-medium passive tracking devices 112 maybe configured in accordance with the passive tracking devices 108discussed above, but may include additional configurations to supportthe transmission of data (e.g., short messages) via an RFID backscatterradio in addition to a BLE radio. In this way, a dual-medium passivetracking device 112 may be energized by an electromagnetic signal andmay output a message via one or both radios (BLE and/or RFID). Theaddition of an RFID backscatter radio to the passive tracking devices108 may increase the cost of the dual-medium passive tracking device byonly, for example, half a cent per unit, but provides a number ofadvantages as the dual-medium passive tracking device 112 realizes theadvantages of both mediums. For example, the dual-medium passivetracking device 112 may maintain the longer read distances of up to 40meters due to the BLE capabilities, but may also maintain the securitymeasures provided by RFID. Furthermore, the dual-medium passive trackingdevices 112 allow a product to be tracked throughout its lifecycle,rather than limited through the supply chain or after the point of sale.

FIG. 2 illustrates an example lifecycle of a product. The exemplarylifecycle is divided into a supply chain side 200 and a post-sale side202. In an example supply chain side, a product may begin its lifecyclein a manufacturing facility 210, from where the product is transportedvia a shipping vehicle 214 (e.g., a truck, a train, a plane, and/or aship). In some scenarios, the product is shipped to a warehouse 218,where the product awaits delivery. In some scenarios, the product maythen be loaded onto a delivery vehicle 222 (e.g., a truck or car) anddelivered to a retail store 226. It is noted that in other scenarios, aseller of the product may ship the product to a consumer directly, ifthe purchase is made via, for example, an ecommerce website or by phone.Once the product reaches the retail store 226, it may be placed in theshelves or kept in inventory until it is purchased at a point of sale230. Once the product is purchased, it can be thought of as in itspost-sale segment of the product lifecycle (e.g., at a home 234,business (not shown), or the like).

In the supply chain side 200 of a product life cycle, most legacysystems rely heavily on RFID. Products are routinely scanned throughoutthe journey in the supply chain and the common form of scanning is doneusing RFID tags and readers. At the point of sale, and once a productreaches its final destination (e.g., a home or business),Bluetooth-enabled devices are more prevalent, which makes BLE a moreconvenient form of tracking. In the example above, the RFIDfunctionality allows a product to be tracked using, for example, anaggregator device 104 while in the manufacturing facility 210, in ashipping vehicle 214, at a warehouse 218, in a delivery vehicle 222,and/or at a retail facility 226. During this process, various partiesinvolved in the supply chain may also use legacy RFID devices to scanthe dual-medium passive tracking device 112 in the normal course ofbusiness. Furthermore, as new technologies emerge (e.g., smart glasses240), these new devices may begin leveraging the Bluetooth-scanningcapabilities of the tracking device 112 and/or may scan visual indiciatrackers 114 affixed to an item. Once a product is at the point of sale230, the dual-medium passive tracking device 112 may be scanned usingBluetooth or RFID, depending on the capabilities of the retailer. Oncethe product is sold, the owner of the product may rely on the Bluetoothcapabilities to track or otherwise inventory the product.

Visual indicia 114 may be any text, marking, pattern, and/or image thatis encoded with a value. Examples of visual indicia 114 may include UPCand QR-Codes. In embodiments, visual indicia 114 (e.g., UPC and/orQR-codes) may be used in the tracking system 100 as a means to track anitem using scanning technologies and/or machine-vision. In embodiments,the visual indicia 114 may be used as a redundancy with the othertracking devices described above. For example, a visual indicia may betracked using a vision system 116 in environments such as a shippingfacility or production line. The value embedded in each visual indicia114 may be a unique value that identifies the item to which it isaffixed from other items. In some embodiments, a central system (e.g.,the backend system) may assign the value to embed in a visual indicia114 before it is printed. In other embodiments, a scheme may beimplemented where each entity having the ability to generate visualindicia. For example, any company that prints visual indicia 114 to beused in the tracking system 100 may be assigned a unique value thatmakes up a portion of the value, which may then be combined with anothervalue that is generated by the company and that is unique with respectto the company, whereby the unique value is associated with the item tobe tracked. It is noted that these techniques for printing values may beused to embed values in other tracking devices of the tracking system.Once printed and assigned to an item, the value may be associated withthe certain item.

A vision system 116 may include one or more cameras that monitor an areaand any devices needed to route the video streams/depth streams to anaggregator device 104 and/or a backend system 120. In some embodiments,the cameras include 3D cameras that capture video and depth information.Alternatively or alternatively, any combination of video cameras,infrared cameras, depth cameras, and the like, may be included in acamera system. A vision system 116 may include a network device (e.g.,WIFI, LTE, etc.) and/or a short-distance communication device (e.g.,Bluetooth enabled chip) that streams the captured stream(s) to anaggregator device 104 and/or a backend system 120.

FIG. 3 illustrates an example passive tracking device 108 (such as adual medium tracking device 112) according to some embodiments of thepresent disclosure. In some embodiments, the passive tracking device 108allows for multi-band operation by simultaneously harvesting energy on afirst frequency band and transmitting on the same frequency band or adifferent frequency band. According to some embodiments, the passivetracking device 108 is configured for multi-mode multi-band operation bycommunicating as a passive BLE or Wi-Fi (e.g., 2.4 GHz) or EPC RFID(e.g., 900 MHz) tag, depending on the signals it receives.

In embodiments, the passive tracking device 108 includes a first antenna302, a second antenna 304, a third antenna 306, an energy harvestingmodule 308, a first transmission module 310, a second transmissionmodule 312, and a mode selection module 314. In some embodiments, thepassive tracking device 108 may further include a sensor module 316 thatincludes one or more different types of sensors and/or an encryptionmodule that encrypts packets that are transmitted by the passivetracking device 108.

In embodiments, the passive tracking device 108 receives energizingsignals and transmits response signals on one or more of a plurality offrequency bands via the first, second, and third antennas 302, 304, 306.As used herein, a response signal may refer to any type of signal thatis transmitted by a passive tracking device 108 in response to beingenergized. Response signals may include RFID signals, beacon signalsthat are transmitted according to the Bluetooth, BLE, or WiFi protocolsignals, or signals transmitted according to any other suitableprotocol. The first antenna 302 is configured to transmit responsesignals on a first frequency band. The second antenna 304 is configuredto receive energizing signals on a second frequency band. The thirdantenna 306 is configured to both receive energizing signals andtransmit response signals on a third frequency band. The first, secondand third frequency bands may be frequency bands commonly used forWi-Fi, Bluetooth, Bluetooth Low Energy (BTE), RFID, or any othersuitable form of signal transmission and/or reception. Example frequencybands that an antenna may receive or transmit at may include 2.4 GHz, 5GHz, 900 MHz, 700 MHz, and/or combinations thereof. In some embodiments,the first and second frequency bands are the same. For example, in someembodiments, the first and second frequency bands may be 2.4 GHz, whilethe third frequency band is 900 MHz. The first, second, and thirdantennas 302, 304, 306 allow a passive tracking device 108 to receiveenergizing signals from and transmit response signals to severaldifferent types of devices over several different frequency bands. Eachof the first, second, and third antennas 302, 304, 306 may be a dipoleantenna, a monopole antenna, an array antenna, a loop antenna, or anyother suitable type of antenna. It is further noted, that in embodimentsthe passive tracking device 108 may include less (e.g., two or less) ormore (four or more) antennas.

The energy harvesting module 308 is configured to at least partiallyconvert RF electrical energy, in the form of alternating currentelectrical energy, from energizing signals received via the first,second, and third antennas 302, 304, 306 to DC electrical energy and toprovide the DC electrical energy to one or more of the mode selectionmodule 314, the first and second transmission modules 310, 312, theencryption module 318, and the sensor module 316. In embodiments, theenergy harvesting module 308 receives an energizing signal at leastpartially made up of RF electrical energy from the second and/or thirdantennas 304, 306. In some embodiments, the energy harvesting module 308receives RF electrical energy (also referred to as an “energizingsignal”) from either or both of the second antenna 304 and the thirdantenna 306. In some embodiments, the energy harvesting module 308 isconfigured to transform energizing signals received from the secondantenna 304 from low-impedance signals to high-impedance signals,thereby increasing an amount of energy to be harvested from thetransformed signals via impedance matching. By converting RF electricalenergy from energizing signals received from the second and/or thirdantennas 304, 306, to DC electrical energy and providing DC electricalenergy to other components of the passive tracking device 108, thepassive tracking device 108 is able to substantially operateindependently of a discrete power source, such as a battery or an AC-DCadapter connected to a power grid.

In some embodiments, the energy harvesting module 308 includes an energystorage device, such as a storage capacitor, that stores energy fortransmission to other components of the passive tracking device 108. Insome embodiments, the energy harvesting module 308 indicates to the modeselection module 314 when a sufficient amount of energy has beenharvested to supply components of the passive tracking device 108. Whena sufficient amount of energy has been harvested by the energyharvesting module 308, the mode selection module 314 may determinewhether to operate the passive tracking device in a first mode (e.g.,BLE or WiFi) or a second mode (e.g., RFID). The mode selection module314 may then determine whether to operate the passive tracking device109 in the first mode or the second mode based on the frequency band ofthe energy harvesting signal and/or the contents thereof (e.g., whetherthe energizing signal was received at 2.5 GHz or 900 MHz and/or whetherthe energizing signal contains RFID commands).

In embodiments, the first transmission module 310 is configured tomodulate response signals for transmission on the first frequency band.For example, the first transmission module 310 may modulate responsesignals (e.g., beacon signals modulated according to the BLE protocolat, for example, 2.4 GHz) when the energy harvested by the energyharvesting module 314 sufficiently energizes the passive tracking device108 and the mode selection module 314 determines that the passivetracking device 102 is to operate in a first mode (e.g., based on thecontents of the energizing signal harvested by the energy harvestingmodule 314). The first transmission module 310 outputs modulatedresponse signals having a carrier frequency substantially equal to thefirst frequency band, such that devices capable of receiving signals onthe first frequency band may receive the response signals.

In embodiments, the response signals may each include one or more datapackets or other suitable data structures. For example, in embodiments,a response signal may include a device ID of the passive tracking device108, which may or may not be encrypted/obscured by the encryption module318. Furthermore, in some embodiments, the first transmission module 310may include additional data in a response signal. For example, the firsttransmission module 310 may obtain sensor data from one or more sensorsof the sensor module 316, which the first transmission module 310encodes into the response signal. In some of these embodiments, thefirst transmission module 310 may be configured with logic (e.g., one ormore rules and/or conditions) that governs the inclusion of additionaldata (e.g., sensor data) in the response signal. For example, the firsttransmission module 310 may be configured to only include sensor data ina response signal if one or more values included in the sensor data isabove or below a threshold. In a specific example, the firsttransmission module 310 may be configured to only include thermal sensordata in the response signal if a measured temperature value exceeds anupper temperature threshold (e.g., >60° C.) or is less than a lowertemperature threshold (e.g., <5° C.). In another specific example, thefirst transmission module 310 may be configured to only include shocksensor data in the response signal if a measured shock value exceeds anacceleration threshold (e.g., >2 G). The foregoing specific examples ofrules and conditions are provided for example only and not intended tolimit the disclosure.

In embodiments, the second transmission module 312 is configured toprepare response signals for transmission on the third frequency band(e.g., 900 MHz). In these embodiments, the second transmission module312 may be configured to output prepared response signals to the thirdantenna 306 for transmission when the passive tracking device 108operates in a second mode. In some embodiments, the second transmissionmodule 312 prepares the response signals by modulating the responsesignals. The passive tracking device 108 operating in the second modemay be advantageous for several reasons, such as to communicate withdevices that can receive signals over the third frequency band, tocommunicate with devices that can understand communication protocolsimplemented by the second transmission module 312 in transmitting overthe third frequency band, to transmit within a suitable range, etc. Inembodiments, the passive tracking device 108 may operate in the secondmode when the response signal is being read by a device that receivessignals via the third frequency band. For example, the reading devicemay energize the passive tracking device 108 with an energizing signalmodulated at 900 MHz and the energizing signal may contain EPC RFIDcommands, thereby indicating that the reading device receives and readssignals provided in accordance with the EPC RFID protocol.

In embodiments, the second transmission module 312 outputs preparedresponse signals having a carrier frequency substantially equal to thethird frequency band, such that devices capable of receiving signals onthe third frequency band may receive the signals. For example, inembodiments, the second transmission module 312 sends and receivessignals within an RFID frequency band (e.g., 900 MHz). In theseembodiments, the second transmission module 312 may adhere to an RFIDcommunication protocol. For example, the second transmission module 312may output signals in accordance with an EPC communication protocol, anISO RFID standard, an ISO/IEC RFID standard, an ASTM RFID standard, orany other suitable standard or protocol. In some embodiments, the secondtransmission module 312 includes a backscatter switch. In theseembodiments, the second transmission module 312 is configured to actuatethe backscatter switch to prepare a signal having a carrier frequencysubstantially equal to the third frequency band for transmission on thethird antenna 306. In some embodiments, the second transmission module312 may prepare and transmit response signals by actuating thebackscatter switch, thereby toggling impedance of the third antenna. Insome embodiments, for example, the second transmission module 312 mayallow the passive tracking device 108 to transmit via the thirdfrequency band using substantially zero energy or a very small amount ofenergy by transmitting on the third frequency band via backscattering anincoming RFID signal. In some embodiments, the second transmissionmodule 312 may also be configured to transmit limited types of data inaccordance with, for example, the EPC communication protocol. In theseembodiments, the response signal output by the second transmissionmodule 312 may be limited to information such as a device identifier ofthe tracking device, and may exclude, for example, sensor data collectedby the sensor module 316. Refraining from including one or more types ofinformation in response signals may allow the passive tracking device108 to further save energy while operating in the second mode andtransmitting via the second transmission module 312 rather thanexpending more energy by operating in the first mode and transmittingvia the first transmission module 310.

In embodiments, the mode selection module 314 is configured to determinewhether the passive tracking device 108 is to transmit in the first modeor second mode. For example, in embodiments the mode selection module314 may determine whether to transmit a response signal using BLE (firstmode) via the first transmission module 310 or RFID (second mode) viathe second transmission module 312. In embodiments, the mode selectionmodule 314 may receive an energizing signal and may determine theoperation mode based on the frequency of the energizing signal and/orthe contents of the signal (e.g., whether there is an RFID header in thesignal followed by a complete RFID message). In some embodiments, thepassive tracking device 108 may operate in the first mode as a default,unless the mode selection module 314 determines that the passivetracking device is to operate in the second mode. In embodiments, thepassive tracking device 108 may operate in the first mode unless one ormore conditions are met, in which case the passive tracking device 108operates in the second mode. In some of these embodiments, the modeselection module 314 may receive signals from the third antenna 306.Upon receiving an energizing signal from the third antenna 306, the modeselection module 314 is configured to determine whether the passivetracking device 108 operates in a first mode or a second mode based onthe contents of the energizing signal.

In example embodiments where first mode corresponds to a BLEcommunication mode and the second mode corresponds to an RFIDcommunication mode, the third antenna may be an RFID antenna thatreceives and transmits according to an RFID protocol, the passivetracking device 108 may be configured to operate in the first mode as adefault, and the mode selection module 314 may select the second modebased on a received energizing signal. For example, when a signal isreceived via the third antenna 306, the mode selection module 314 maydetermine whether the signal contains an EPC header and a correspondingEPC command. In this scenario, the mode selection module 314 mayinstruct the second transmission module 312 to respond in the secondmode. If the energizing signal is received via the second antenna 304and/or the received signal does not contain an EPC header and/orcontains a command to operate in the first mode, the mode selectionmodule 314 operates in the first mode. When the mode selection module314 determines that the passive tracking device 108 operates in thesecond mode, the passive tracking device 108 transmits a signal via thethird antenna 306 on the third frequency band, such that devices capableof receiving signals on the third frequency band may receive the signal.In some embodiments, the mode selection module 314 determines that thepassive tracking device 108 operates in the first mode if no signal hasbeen received on the third antenna 306 and only determines that thepassive tracking device 108 operates in the second mode if both a signalhas been received on the third antenna 306 (e.g., on the third frequencyband) and the signal received on the third antenna 306 contains amessage of a specified type, e.g., a message containing an RFID messageheader. If the message is not of the specified type, e.g., the messagedoes not contain an RFID header or is otherwise invalid, the modeselection module 314 determines that the passive tracking device 108operates in the first mode.

In embodiments, the passive tracking device includes a sensor module316. In these embodiments, the sensor module 316 may include one or moresensors that generate sensor data. Examples of sensors may include, butare not limited to, temperature sensors (e.g., thermistors, heat fluxsensors, or bulk acoustic wave temperature sensors), light sensors(e.g., photon detectors), sound sensors (capacitive-based sound sensor),humidity sensors (capacitive-based humidity sensors, resistive-basedhumidity elements, thermal-based humidity sensors), motion sensors(e.g., accelerometers, gyroscopes), shock sensors (e.g., sensors thatare triggered when a threshold amount of shock is detected),acceleration sensors (e.g., accelerometers, gyroscopes), or any othersuitable sensors. In some embodiments, the sensors are configured toprovide real-time (e.g., substantially instantaneous) readings that areindicative of one or more conditions of the environment of the passivetracking device 108 at the time that the passive tracking device 108 ispowered. For example, values such as temperature and humidity may bemeasured upon the passive tracking device 108 being energized. In someembodiments, the sensors are configured to indicate whether one or moreconditions had been met at some point before the passive tracking device108 is energized. For example, a sensor may record whether a certaincondition has been reached (e.g., light was detected by the sensor, aminimum amount of force was detected, a temperature or humidity exceededa lower limit or went below a lower limit, etc.). In these embodiments,the state of the sensor may be indicative of an occurrence of a specificcondition, such that sensor data read before the occurrence of thespecific condition is different than sensor data read after theoccurrence of the specific condition. In this way, an approximation ofwhen the specific condition occurred may be determined from a series ofresponses from the passive tracking device 108. In some embodiments, oneor more of the sensors may record that a condition has been met withoutthe one or more sensors being powered. For example, a light sensor mayinclude a photosensitive film that undergoes a measurable change whenexposed to light, or a shock sensor may include a component that changesphysical position only upon the shock sensor receiving an amount offorce receiving a threshold, thereby indicating that the condition hasbeen met. Upon receiving an energizing signal or otherwise preparing asignal for transmission, the sensor module 316 may indicate to one ormore of the first and second transmission modules 310, 312 that thecondition has been met such that the passive tracking device 108 caninclude information related to the condition having been met in one ormore signal transmissions, such as time stamps indicating when thecondition was met. In some embodiments, one or more of the sensors maybe a bulk acoustic wave sensor (e.g., a bulk acoustic wave temperaturesensor).

In embodiments, the sensor module 316 is configured to output sensordata generated by the one or more sensors to the first transmissionmodule 310 only when the passive tracking device 108 communicates in thefirst mode. In some embodiments, the sensor data is not transmitted whenoperating in the second mode. Alternatively, in some embodiments, thesensor module 316 is configured to transmit sensor data generated by theone or more sensors to the second transmission module 312 when thepassive tracking device 108 communicates in the second mode or the firstmode. In these embodiments, upon receiving sensor data from the sensormodule 316, the first transmission module 310, and the secondtransmission module 312 are each configured to include the sensor datain modulated signals transmitted by the first antenna 304 and the thirdantenna 306, respectively.

In some embodiments, the passive tracking device 108 includes a storagedevice, e.g., non-volatile random-access memory (NVRAM). In some ofthese embodiments, the sensor module 316 may be configured to storesensor data in the storage device.

It should be appreciated that while the sensor module 316 is describedin context of multi-mode embodiments of the passive tracking device 108,the sensor module 316 may be similarly or substantially identicallyimplemented in single-mode embodiments of the passive tracking device108, multi-mode tracking devices 102, paired tracking devices 104, andthe like.

In some embodiments, the encryption module 318 is configured to encryptmessages transmitted by the passive tracking device 108. In some ofthese embodiments, the encryption module 318 only encrypts messagestransmitted using the first mode (e.g., BLE or Wi-Fi) when the protocolused in the second mode (e.g., EPC RFID) does not support a similarencryption algorithm. In some embodiments, the encryption module 318 isconfigured to output encrypted messages (e.g., to the first transmissionmodule 310) upon being energized by the energy harvesting module 308. Insome embodiments, the encryption module 318 utilizes a secret key and asecret pattern to encrypt a response message, as discussed throughoutthis disclosure, to obtain an encrypted message (e.g., an encrypted datapacket). The encryption module 318 may output the encrypted message to,for example, the first transmission module 310, which in turn transmitsthe encrypted message via the first antenna 302.

In some embodiments, the encryption module 318 may be further configuredto output the encrypted message to, for example, the second transmissionmodule 312, which in turn transmits the encrypted module via the thirdantenna 364. Upon receiving an encrypted message from the encryptionmodule 318, the first transmission module 310 and the secondtransmission module 312 are each configured to include the encryptedmessage in modulated and/or prepared signals transmitted by the secondantenna 304 and the third antenna 306, respectively. Encrypted messagesencrypted by the encryption module 318 may include an identifier of thepassive tracking device 108, such as an RFID identifier or a BLEidentifier. In some embodiments, EPC identifiers are encrypted fortransmission over BLE. It should be appreciated that while theencryption module 318 is described in context of multi-mode embodimentsof the passive tracking device 108, the encryption module 318 may besimilarly or substantially identically implemented in single-modeembodiments of the passive tracking device 108 (e.g., passive trackingdevices 108 that transmit using BLE only), the multi-mode trackingdevices 102, the paired tracking devices 104, and other suitabletracking devices.

It is noted that in some embodiments, the passive tracking device ofFIG. 3 may be a single mode passive tracking device. For example, insome embodiments, the passive tracking device 108 may be implemented asa BLE tracking device without the third antenna 308, the secondtransmission module 312, and the mode selection module 314. In some ofthese embodiments, the passive tracking device 108 may be energizedusing the second antenna at a first frequency band (e.g., 2.5 GHz) andmay transmit response signals using the first antenna using the samefrequency band (e.g., 2.5 GHz). In other embodiments, the passivetracking device 108 may be implemented as a BLE tracking device withoutthe second transmission module 312 and the mode selection module 314. Inthese embodiments, the passive tracking device 108 may harvest energyusing the second antenna 304 at a first frequency band (e.g., 2.5 GHz)or the third antenna 306 at a second frequency band (e.g., 900 MHz), butwill only transmit at the first frequency band (e.g., 2.5 GHz). Thepassive tracking device 108 may be configured in a similar manner toonly support RFID transmissions, whereby the device may not include thefirst transmission module 310 and the mode selection module 314.

FIG. 4 illustrates example components of a passive tracking device 108(e.g., the passive tracking device 108 of FIG. 3) according to someembodiments of the present disclosure. In some embodiments, a firstantenna 302 is configured to transmit Bluetooth Low Energy (BLE) on a2.4 GHz frequency band. In embodiments, a second antenna 304 isconfigured to receive BLE on the 2.4 GHz frequency band, which mayenergize the passive tracking device 108. It is noted that the firstantenna 302 and the second antenna 304 may transmit and receive,respectively, according to other suitable protocols, such as Bluetooth,WiFi, and other suitable short range communication protocols. Inembodiments, a third antenna 306 is configured to transmit and receiveRFID signals on a 900 MHz frequency bands, for example, according to theElectronic Product Code (EPC) C1G2 standard, such that the passivetracking device 108 may be energized and may transmit responses via thethird antenna 306.

In embodiments, the passive tracking device 108 includes a transformer408, an energy harvester 410, a clamp circuit 412, a storage capacitor414, and a voltage regulator 416, which may be configured to harvestenergy to energize the passive tracking device 108. In embodiments, thetransformer 408 receives low-impedance RF electrical energy, in the formof low-impedance alternating current electrical energy, from BLE and/orWi-Fi signals received via the second antenna 304 and converts thelow-impedance RF electrical energy into high-impedance RF electricalenergy. The transformer 408 outputs the high-impedance RF electricalenergy to the energy harvester 410. Due to impedance matching, theenergy harvester 410 can harvest more energy from the high-impedance RFelectrical energy than it would be able to harvest from thelow-impedance RF electrical energy that is received by the transformer408 from the second antenna 304. The transformer 408 may be a bulkacoustic wave RF voltage transformer, an air-core transformer, aferrite-core transformer, a transmission-line transformer, or any othersuitable type of transformer. In some embodiments, the energy harvester410 receives RF energy from the second antenna 304 and the third antenna306 and performs smoothing on the RF energy. The RF energy may passthrough one or more diodes (not shown) before reaching the energyharvester 410, thereby removing a negative portion of the RF energy. Insome embodiments, the energy harvester 410 outputs a smoothed energywave, such as a sine wave with peaks approximately equal to 6V-10V, tothe clamp circuit 412. The clamp circuit 412 is configured to shift a DCvalue of the smoothed energy wave and limit peaks of the smoothed energywave such that the smoothed energy wave is suitable to be stored in thestorage capacitor 414 and power other components of the passive trackingdevice 108. The clamp circuit 412 then transmits the smoothed energywave to the storage capacitor 414 and to the voltage regulator 416. Thestorage capacitor 414 is configured to store energy and output energy tothe voltage regulator 416 as the energy is needed to power the passivetracking device 108. The voltage regulator 416 is configured to provideenergy from the clamp circuit 412 and the storage capacitor 414 to othercomponents of the passive tracking device 108 via the power bus 418 andensure that other components of the passive tracking device 108 receivea relatively constant amount of voltage, e.g., 2V. In embodiments, thevoltage regulator 416 may be a low-dropout regulator.

In embodiments, the passive tracking device 108 is configured tomodulate BLE for transmission on a 2.4 GHz frequency band when thepassive tracking device 108 operates in the first mode. In embodiments,the passive tracking device 108 includes a reference oscillator 404, anAC power source 407, a phase-locked loop (PLL) 402, an amplifier 403,the GFSK modulator 405, and a state machine 426. Prior to transmissionvia the first antenna 302, the state machine 426 transmits to the GFSKmodulator 405 one or more of identifying information, e.g., an EPC ID,and sensor data in a format that conforms to BLE standards. In someembodiments, the passive tracking device 108 includes non-volatilememory (NVM) 424, and the GFSK modulator 405 reads the identifyinginformation and/or sensor data from the NVM 424. The GFSK modulator 405,the PLL 402, the AC power source 407, and the reference oscillator 404work in conjunction to modulate a signal having a carrier frequency of2.4 GHz and containing the information supplied by the state machine 426to the GFSK modulator 405. The amplifier 403 then amplifies the signaland transmits the signal to the first antenna 302 for transmission. Insome embodiments, to facilitate needs of small size, low cost, thermalresistance, contamination resistance, vibration resistance, humidityresistance, or a combination thereof, the reference oscillator 404 maybe a bulk acoustic wave oscillator, such as is disclosed in US PatentApplication Publication No. 2019/0074818 to Lal et al., the entirety ofwhich is hereby incorporated by reference. In other embodiments, thereference oscillator 404 may be any other suitable type of oscillators,such as a MEMS oscillator or a crystal.

In embodiments, the passive tracking device 108 is configured to prepareRFID signals (e.g., RFID C1G2) for transmission on a 900 MHz frequencyband when the passive tracking device 108 operates in the second mode.In embodiments, the passive tracking device includes an EPC modem 422,such as an EPC C1G2 modem, and a backscatter switch 406. When thepassive tracking device 108 operates in the second mode in response toreceiving an RFID signal having a carrier frequency of 900 MHz via thethird antenna 306, the EPC modem 422 generates an RFID message accordingto the C1G2 RFID standard format. The EPC modem 422 then actuates thebackscatter switch 406 to prepare the same 900 MHz signal previouslyreceived via the third antenna 306, such that the same 900 MHz signalcontains the RFID message generated by the EPC modem 422. The message isthen transmitted via the third antenna 306. In some embodiments, theRFID message includes one or more of a device identifier of the passivetracking device and sensor data. The EPC modem 422 may read theidentifier from the NVM 424 before generating the RFID message. Inembodiments, the EPC modem 422 may obtain the sensor data from thesensor module 316.

In embodiments, the passive tracking device 108 includes a mode selector420 configured to receive RFID signals via the third antenna 306 on the900 MHz frequency band. Upon receiving an RFID signal from the thirdantenna 306, the mode selector 420 is configured to determine whetherthe passive tracking device 108 operates in the first mode or the secondmode. When the mode selector 420 determines that the passive trackingdevice 108 operates in the first mode, the passive tracking device 108transmits a response signal (e.g., a BLE beacon signal) via the firstantenna 302 on the 2.4 GHz frequency band, such that devices capable ofreceiving the response signal (e.g., BLE beacon signal) on the 2.4 GHzfrequency band may receive the signal. When the mode selector 420determines that the passive tracking device 108 in the second mode, thepassive tracking device 108 transmits an RFID signal via the thirdantenna 306 on the 900 MHz frequency band, such that devices capable ofreceiving RFID signals on the 900 MHz frequency band may receive theresponse signal. In some embodiments, the mode selector 420 includes alow power timer (e.g., a low power 32 kHz timer) (not shown).

In some embodiments, the mode selection module 314 is configured todetermine when to transmit a response signal when operating in the firstmode based on the amount of energy harvested by the energy harvester 410and/or stored by the storage capacitor. For example, if the passivetracking device 108 receives at least 0 dBm of RF power, the passivetracking device 108 may transmit a BLE beacon signal as quickly and asoften as possible. If the passive tracking device 108 receives between−20 dBm and 0 dBm of RF power, the passive tracking device 108 maytransmit a BLE beacon signal only at an interval according to aninterval timer in order to save energy. If the passive tracking device108 receives less than −20 dBm of RF power, the passive tracking device108 may transmit a BLE beacon signal only upon the amount of energystored exceeding approximately 1 μJoule. The threshold power valuesprovided above (0 dBm and −20 dBm) are provided for example and notintended to limit the scope of the disclosure.

In some embodiments, when the passive tracking device 108 operates inthe first mode (e.g., BLE), the state machine 426 may be configured todetermine whether to include sensor data in the response signal based onwhether the value(s) of the sensor data meet a requisite condition(e.g., if one or more values included in the sensor data is above orbelow a threshold). For example, the state machine 426 may be configuredto include sensor data in a response signal (e.g., a BLE beacon signal)if one or more temperature values included in thermal sensor dataexceeds a temperature threshold (e.g., 50° C.) or is less than a lowertemperature threshold (e.g., <0° C.). In another example, the statemachine 426 may be configured to include sensor data in a responsesignal (e.g., a BLE and/or Wi-Fi signal) if an acceleration valueincluded in shock sensor data exceeds a shock threshold (e.g., 3 G).

It is noted that in some embodiments, the passive tracking device ofFIG. 4 may be a single mode passive tracking device (e.g., BLE only,WiFi only, or RFID only). For example, in some embodiments, the passivetracking device 108 may be implemented as a BLE tracking device withoutthe third antenna 306, the backscatter switch 406, the EPC modem 422, orthe mode selector 4230. In some of these embodiments, the passivetracking device 108 may be energized using the second antenna 304 at afirst frequency band (e.g., 2.5 GHz) and may transmit response signalsusing the first antenna 302 using the same frequency band (e.g., 2.5GHz). In other embodiments, the passive tracking device 108 may beimplemented as a BLE tracking device without the backscatter switch 406,the EPC modem 422, or the mode selector 4230. In these embodiments, thepassive tracking device 108 may harvest energy using the second antenna304 at a first frequency band (e.g., 2.5 GHz) or the third antenna 306at a second frequency band (e.g., 900 MHz), but will only transmit atthe first frequency band (e.g., 2.5 GHz). The passive tracking device108 may be configured in a similar manner to only support RFIDtransmissions, whereby the device may not include the components used totransmit in the first mode.

FIG. 5 is a flowchart depicting an example set of operations of a method500 for determining whether the passive tracking device 108 is tooperate in the first mode or the second mode, according to someembodiments of the present disclosure. The method 500 may be performedby any suitable component of a multi-mode passive tracking device 108(e.g., mode selection module 314 or mode selector 420). For purposes ofexplanation, the method 500 is described with respect to the passivetracking device 108 of FIG. 3 and the components thereof. It should beappreciated that the method 500 may be performed substantially similarlyby any other suitable devices without departing from the scope of thedisclosure.

At 502, the passive tracking device 108 powers the mode selection module314. As the mode selection module 314 generally requires little energyto function, the mode selection module 314 may stay powered afterperformance of the method 500 and may remain powered from a previousperformance of the method 500 prior to a subsequent performance of themethod 500. In some embodiments, the mode selection module 314 ispowered before any other component of the passive tracking device 108when energizing signals are received, thereby allowing the modeselection module 314 to perform the method 500 while one or more othercomponents of the passive tracking device 108 remain unpowered.

At 504, the passive tracking device 108 receives an energizing signalvia the second antenna 304 or the third antenna 306.

At 506, the mode selection module determines whether the energizingsignal was received via the second antenna 304 or the third antenna 306.If the energizing signal was received via the second antenna 304, thepassive tracking device 108 operates in the first mode (518). If theenergizing signal was received via the third antenna 306, the passivetracking device 108 performs operation 508. In embodiments where thefirst mode is the default mode of operation, the passive tracking device108 proceeds to operation 518, unless the energizing signal is receivedvia the third antenna 306.

At 508, the mode selection module waits for a first duration (e.g., 2.5ms) to determine whether the energizing signal contains an RFID header,such as a start of an EPC ultra-high frequency (UHF) RFID-formattedcommand.

At 510, the passive tracking device 108 determines whether the RFIDheader was detected during the first duration. If the energizing signalcontains the RFID header, the passive tracking device 108 performsoperation 510. If the energizing signal does not contain the RFIDheader, the passive tracking device 108 operates in the first mode, asshown at operation 518.

At 512, the mode selection module 314 waits for a second duration, e.g.,up to 10 ms, such that the second transmission module has enough time toreceive and parse an RFID-formatted command, e.g., an EPC UHFRFID-formatted command, received via the energizing signal.

At 514, the passive tracking device 108 determines whether theRFID-formatted command was detected received and parsed during thesecond duration. If the RFID-formatted command was received and parsed,the passive tracking device 108 operates in the second mode, as shown atoperation 516. If the RFID-formatted command was received and parsed,the passive tracking device 108 operates in the first mode, as shown atoperation 518.

At 516, the passive tracking device 108 operates in the second mode(e.g., RFID). In some embodiments, the passive tracking device 108operates in the second mode for a period of time, e.g., 40 ms, or untila certain condition has been met, e.g., no RFID-formatted command hasbeen received for 40 ms. At 518, the passive tracking device 108operates in the first mode (e.g., BLE).

FIG. 6 is a flowchart depicting examples operations of a method 600 foroperating a passive tracking device 108 according to some embodiments ofthe present disclosure. In some embodiments, the mode selection module314, the first transmission device 310, the second transmission device312, the sensor module 316, and the encryption module 318 perform partsof the method 600. In some embodiments, the mode selection 420, the EPCmodem 422, the energy harvester 410, the state machine 426, and othercomponents shown in FIG. 4 perform parts of the method 600. Forsimplicity of explanation, the method 600 is described with respect tothe passive tracking device 108 of FIG. 3. It should be appreciated thatthe method 600 may be performed substantially similarly by embodimentsof the passive tracking device 108 including components shown in FIG. 4and described in relevant descriptions of embodiments.

At 602, the passive tracking device 108 powers the mode selection module314. As the mode selection module 314 generally requires little energyto function, the mode selection module 314 may stay powered afterperformance of the method 600 and may remain powered from a previousperformance of the method 600 prior to a subsequent performance of themethod 600. In some embodiments, the mode selection module 314 ispowered before any other component of the passive tracking device 108when energizing signals are received, thereby allowing the modeselection module 314 to perform the method 600 while one or more othercomponents of the passive tracking device 108 remain unpowered.

At 604, the passive tracking device 108 receives an energizing signalvia the second antenna 304 or the third antenna 306.

At 606, the mode selection module 314 determines whether the energizingsignal was received via the second antenna 304 or the third antenna 306.If the energizing signal was received via the second antenna 304, thepassive tracking device 108 proceeds to operation 618. If the energizingsignal was received via the third antenna 306, the passive trackingdevice 108 performs operation 608. In embodiments where the first modeis the default mode of operation, the passive tracking device 108proceeds to operation 618 unless the energizing signal is received viathe third antenna 306.

At 608, the mode selection module waits for a first duration (e.g., 2.5ms) to determine whether the energizing signal contains an RFID header,such as a start of an EPC UHF RFID-formatted command.

At 610, the passive tracking device 108 determines whether the RFIDheader was detected during the first duration. If the energizing signalcontains the RFID header, the passive tracking device 108 performsoperation 612. If the energizing signal does not contain the RFIDheader, the passive tracking device 108 proceeds to operation 618.

At 612, the mode selection module 314 waits for a second duration (e.g.,up to 10 ms), such that the second transmission module has enough timeto receive and parse an RFID-formatted command (e.g., an EPC UHFRFID-formatted command) received via the energizing signal.

At 614, the passive tracking device 108 determines whether anRFID-formatted command was detected (e.g., received and parsed) duringthe second duration. If an RFID-formatted command was detected, thepassive tracking device 108 performs operation 616. If theRFID-formatted command was received and parsed device 108 proceeds tooperation 618.

At 616, the second transmission module 312 prepares and transmits asecond response signal in the second mode. In embodiments, the passivetracking device 108 transmits the second response signal using an RFIDprotocol in an EPC UHF RFID message.

At 618, the first transmission module 310 determines whether the passivetracking device 108 is to include sensor data in the first responsesignal. If the passive tracking device 108 is to include sensor data inthe first response signal, the passive tracking device 108 performsoperation 620. If the passive tracking device 108 does not need toinclude sensor data in the first response signal (e.g., the device doesnot include a sensor module 316 or there is no sensor data to report),the passive tracking device 108 moves on to operation 622.

At 620, the first transmission module 310 obtains sensor data collectedby the sensor module 316. In some embodiments, the first transmissionmodule 310 receives the sensor data from the sensor module 316 inresponse to the sensor module 316 being energized. The sensor data maybe substantially instantaneous (e.g., captured when the device 108 isenergized) or may be previously determined (e.g., a state of the devicetripped a sensor prior to the device 108 being energized). Additionallyor alternatively, the first transmission module 310 may obtain sensordata from a memory device of the passive tracking device 108. Inembodiments, the first transmission module 310 encodes the sensor datain a data packet or other suitable data structure, which is modulated inthe first response signal discussed below.

At 622, the first transmission module 310 begins modulating the firstresponse signal on a first frequency band (e.g., 2.5 GHz). If thepassive tracking device 108 is configured to include sensor data in thefirst response signal, the first transmission module 310 modulates thefirst response signal such that the modulated first response signalincludes the sensor data. In embodiments, the contents of the firstresponse signal are encoded in accordance with a BLE protocol, or anyother suitable protocol (e.g., WiFi).

At 624, the first transmission module 310 determines whether the poweravailable to the passive tracking device 108 for transmission is greaterthan a first threshold (e.g., 0 dBm). If the power available fortransmission is greater than the first threshold, the first transmissionmodule 310 outputs the first modulated response signal for transmissionvia the first antenna 302, and the first antenna 302 transmits the firstmodulated response signal, as shown at 9126. If the power available fortransmission is not greater than the first threshold, the passivetracking device 108 determines whether the power available to thepassive tracking device 108 for transmission is greater than a secondthreshold (e.g., −20 dBm), as shown at 628. If the available power fortransmission is greater than the second threshold, the passive trackingdevice 108 outputs the first modulated response signal for transmissionvia the first antenna 302 after an interval of time (e.g., 5 s), and thefirst antenna 302 transmits the first modulated response signal afterreceiving the first modulated response signal, as shown at 630. Theinterval of time allows for the passive tracking device 108 to receivemore energy for transmitting the modulated first response signal thanmay have been available upon performance of operation 628. If the poweravailable to the passive tracking device 108 for transmission is notgreater than the second threshold, the passive tracking device 108determines whether the mode selection module 314 is still powered. Ifthe mode selection module 314 is still powered, the passive trackingdevice 108 outputs the first modulated response signal for transmissionvia the first antenna 302 when the energy stored by the passive trackingdevice 108 is sufficient to power the device 108 (e.g., the amount ofenergy required to transmit the first modulated response signal), andthe first antenna 302 transmits the first modulated response signalafter receiving the first modulated response signal, as shown at 634.Otherwise, the passive tracking device 108 resets itself, as shown at636, and thereafter returns to operation 602.

FIG. 7 is a flowchart depicting a method 700 for authenticating atracking device according to some embodiments of the present disclosure.The method 700 is disclosed with respect to a tracking device, a readingdevice, and an authenticating device. The tracking device may be anysuitable tracking device, including a passive tracking device 108, 112,or a powered tracking device 102, 106. In embodiments, theauthentication device may be a back end server that includes anauthentication server (e.g., the backend server 120 of FIG. 1).Alternatively, in some embodiments, the authentication device may be astand-alone authentication server that performs authentication servicesfor tracking devices. In some embodiments, the authentication device maybe an aggregator device 104 that authenticates tracking devices 102,106, 108, and/or 112 in the vicinity of the aggregator device 104. Thereading device is optional. In these embodiments, the reading device maybe, for example, an aggregator device 104, a user device 130, or anAR-enabled user device 140. Furthermore, while the reading device isdescribed below as energizing the tracking device, it is understood thata passive tracking device 108 may be energized by a different devicethan the reading device. For example, an exciter 110 may energize thedevices, while an aggregator device 104, a user device 130, or anAR-enabled user device 140, receives the response signals.

At 702, the reading device energizes the tracking device. Inembodiments, the reading device broadcasts the energizing signal on afrequency band (e.g., 2.5 GHz or 900 MHz).

At 704, the tracking device receives the energizing signal. Inembodiments where the tracking device is a passive tracking device, theenergizing signal may energize the passive tracking device, which causesthe tracking device to begin operation.

At 706, the tracking device generates an encrypted message indicating adevice identifier of the tracking device. In some embodiments, thetracking device generates a message that contains a device identifier ofthe tracking device, such that the device identifier uniquely identifiesthe tracking device. In these embodiments, the tracking device mayencrypt the message to obtain the encrypted message, for example, usinga secret key that is known by the tracking device and the authenticatingdevice. In other embodiments, the tracking device may encrypt themessage to obtain the encrypted message, for example, using a secret keyof the tracking device and a public key of the authentication device.

In some embodiments, the tracking device may first obscure the deviceidentifier prior to encrypting the message containing the deviceidentifier. In some of these embodiments, the tracking device obscuresthe device identifier using a random N-bit string that is generated uponthe device being energized, and a secret pattern that is known by thetracking device and the authenticating device. An example method forgenerating the encrypted message is described with respect to FIG. 8. Itis appreciated that other methods of encrypting the message may beimplemented by the tracking device without departing from the scope ofthe disclosure.

At 708, the tracking device transmits the encrypted message to thereceiving device. The tracking device may transmit the encrypted messagein any suitable manner, including the various manners described in thedisclosure. For example, the tracking device may modulate a responsesignal at the frequency band used to receive the energizing signal, suchthat the modulated response signal includes the encrypted message.

At 710, the reading device receives the encrypted message and transmitsthe encrypted message to the authentication device. In some embodiments,the reading device receives the modulated response signal and reads theencrypted message from the modulated response signal. The reading devicemay extract the encrypted message from the modulated response signal andmay route the encrypted message to the authentication device, forexample, via a communication network (e.g., the Internet or a cellularnetwork).

At 712, the authentication device receives the encrypted message.

At 714, the authentication device authenticates the tracking devicebased on the encrypted message. In some embodiments, the authenticationmay decrypt the message using, for example, the secret key of thetracking device. In some of these embodiments, an unencrypted headerportion of the encrypted message may include a secret key identifier ofthe secret key used to encrypt the message. The authentication devicemay retrieve the secret key from a set of secret keys based on thesecret key identifier and may decrypt the encrypted message using theretrieved secret key. In embodiments where the encrypted message wasencrypted using a secret key/public key pair, the unencrypted headerportion of the encrypted message may include a public key of thetracking device. In these embodiments, the authentication device maydecrypt the encrypted message using the public key of the trackingdevice and a private key of the authentication device. Once decrypted,the authentication device may determine the device identifier containedin the decrypted message. In embodiments where the device identifier wasobscured by the tracking device using a secret pattern, the trackingdevice may determine the device identifier from the obscured deviceidentifier based on the secret pattern (as discussed with respect toFIG. 9). The authentication device may then determine whether the deviceidentifier is a valid device identifier. In some embodiments, theauthentication device maintains a list of known device identifiers thatindicates the device identifiers of all the tracking devices that areable to be authenticated by the authenticating device. In theseembodiments, the authentication device may cross reference the deviceidentifier obtained from the decrypted message with the list of knowndevice identifiers to determine whether the device identifier appears inthe list. If so, the authentication device determines that the trackingdevice is authenticated. Otherwise, the authentication device determinesthat it cannot authenticate the device. Once a determination is maderegarding the tracking device's authenticity, the authentication devicemay provide a notification to a relevant device or system. For example,the authentication device may notify the reader device and/or thebackend system that the device has been authenticated.

In embodiments, the foregoing method 700 may be implemented as anauthentication service that authenticates tracking devices, so as todeter counterfeiting of tracking devices. The authentication service maybe offered by a manufacturer of the tracking devices or by a third partyprovider.

FIG. 8 is a flowchart depicting a method 800 for generating an encryptedmessage used to authenticate a tracking device according to someembodiments of the present disclosure. The method 800 may be performedby any suitable type of tracking device. In some embodiments, the methodis performed by an encryption module of a passive tracking device (e.g.,FIG. 3 or FIG. 4). In some of these embodiments, the method is performedupon the passive tracking device 108 being energized and for inclusionin a response signal.

At 802, the tracking device obtains a device identifier of the trackingdevice. The device identifier may uniquely identify the tracking devicefrom other tracking devices. In embodiments, the tracking device mayobtain the device identifier from the nonvolatile memory of the trackingdevice.

At 804, the tracking device generates a random N-bit string. Inembodiments, the tracking device may generate a different N-bit stringeach time the method is executed, so as to ensure that the N-bit stringis not repeated. The tracking device may include a random numbergenerator that generates the random N-bit string or may generate therandom N-bit string in any other suitable manner.

At 806, the tracking device inserts the N-bit string into the deviceidentifier according to a shared secret pattern known by the trackingdevice to obtain an obscured device identifier. The shared secretpattern (or “secret pattern) may be known by the tracking device and oneor more authentication devices that can authenticate the trackingdevice. In some embodiments, the secret pattern defines N differentinsertion slots, such that each insertion slot respectively defines abit position of the device identifier where a respective bit of therandom N-bit string is inserted. For example, in a message containing upto 8 bytes and where the N-bit string is a 6-bit string, an examplesecret pattern may define six bit positions (e.g., 1, 5, 16, 30, 42, 50)for inserting the bits of a random 6-bit string into the deviceidentifier of the tracking device. In this example, the passive trackingdevice may insert the first bit of the 6-bit string bit between thefirst bit and a second bit of the device identifier, the second bit ofthe 6-bit string bit between the fifth and sixth bit, the third bit ofthe 6-bit string bit between the sixteenth and the seventeenth bit, thefourth bit of the 6-bit string bit between the 30^(th) and 31^(st) bit,the fifth bit of the 6-bit string bit between the 42^(nd) and 43^(rd)bit, and the sixth bit of the 6-bit string bit between the 50^(th) and51^(st) bit. In this example, the resultant string is the obscureddevice identifier. In some embodiments, the transmit device may furtherstore a secret pattern identifier that identifies the shared secretpattern from secret patterns used by other devices. As discussed withrespect to operation 808, the secret pattern identifier may be includedin the encrypted portion of an encrypted transmit message or in theunencrypted header of the encrypted transit message.

By utilizing a different random N-bit string to insert into the messageto be encrypted (e.g., the device ID) at each iterative transmission,the encrypted message is ensured to vary between transmissions despitecontaining the same device ID and being encrypted by the same secretkey. In this way, interlopers wishing to replicate a tracking device maybe prevented from replicating an encrypted transmit message sent by thetracking device and intercepted by the interloper.

At 808, the tracking device generates a transmit message based on theobscured device identifier and encrypts the transmit message. In someembodiments, the body of the transmit message contains only the obscureddevice identifier. In other embodiments, the body of the transmitmessage contains additional data as well. For example, in someembodiments, the body of the transmit message may include the secretpattern identifier of the secret pattern. The tracking device may thenencrypt the body of the transmit message. The tracking device mayencrypt the body of the transmit message in any suitable manner.

In some embodiments, the tracking device may encrypt the body of thetransmit message using a shared secret key that is known by the trackingdevice and the authentication device. The shared secret key may be anumeric value that is used to encrypt the device ID. The shared secretkey (and the secret key identifier) may be stored in the nonvolatilememory of the tracking device and may be used by the passive trackingdevice to encrypt the body of the transmit message (e.g., a string ofbits). In these embodiments, the tracking device may include the secretkey identifier of the shared secret key in the unencrypted header of theencrypted message. In some embodiments, the unencrypted header of theencrypted transmit message may further include the secret patternidentifier of the shared secret pattern used to generate the obscureddevice identifier.

In some embodiments, the tracking device may encrypt the body of thetransmit message using a secret key/public key pair. In theseembodiments, the tracking device may encrypt the body of the transmitmessage using a secret key of the tracking device that is only known bythe tracking device and a public key of the authentication device, whichmay also be known by the tracking device and/or received in theenergizing signal. In some of these embodiments, the tracking device mayinclude public key of the tracking device in the unencrypted header ofthe encrypted message. In some embodiments, the unencrypted header ofthe encrypted transmit message may further include the secret patternidentifier of the shared secret pattern used to generate the obscureddevice identifier.

At 810, the tracking device transmits the encrypted transmit message.The tracking device may transmit the encrypted transmit message in anysuitable manner, including the various manners described in thedisclosure. For example, the tracking device may modulate a responsesignal at the frequency band used to receive the energizing signal(e.g., 2.5 GHz), such that the modulated response signal includes theencrypted transmit message.

FIG. 9 is a flowchart depicting a method 900 for authenticating atracking device based on a received encrypted transmit message accordingto some embodiments of the present disclosure. The method 900 may beperformed by any suitable type of authentication device. In embodiments,the authentication device may be a back end server that includes anauthentication server (e.g., the backend server 120 of FIG. 1).Alternatively, in some embodiments, the authentication device may be astand-alone authentication server that performs authentication servicesfor tracking devices. In some embodiments, the authentication device maybe an aggregator device 104 that authenticates tracking devices 102,106, 108, and/or 112 in the vicinity of the aggregator device 104.

At 902, the authentication device receives the encrypted transmitmessage. The authentication device may receive the encrypted transmitmessage directly from the tracking device or may receive the encryptedtransmit message from an intermediate device (e.g., a reading device).

At 904, the authentication device decrypts the encrypted transmitmessage. The authentication device may decrypt the encrypted transmitmessage in any suitable manner.

In embodiments where the message was encrypted using a shared secretkey, the authentication device may read the secret key identifier fromthe unencrypted header portion of the encrypted transmit message. Inthese embodiments, the authentication device may decrypt the encryptedportion of the encrypted message using the shared secret key to obtainthe body of the transmit message, including the obstructed deviceidentifier.

In embodiments where the message was encrypted using a secret key/publickey pair, the authentication device may read the public key of thetracking device from the unencrypted header portion of the encryptedtransmit message. In these embodiments, the authentication device maydecrypt the encrypted portion of the encrypted message using the publickey of the tracking device and the private key of the authenticationdevice to obtain the body of the transmit message, including theobstructed device identifier.

At 906, the authentication device extracts N bits from the obstructeddevice identifier to obtain a device identifier. In some embodiments,the authentication device may obtain a secret pattern identifier fromthe transmit message. As discussed, the secret pattern identifier mayappear in the unencrypted portion of the transmit message or in theencrypted body of the transmit message. Once the authentication devicedetermines the secret pattern identifier, the authentication device mayretrieve the shared secret pattern of the tracking device from memory.The authentication device may then extract N bits from the obstructeddevice identifier to obtain the secret pattern identifier. For example,borrowing from the example of FIG. 8, the authenticating device mayremove the second bit, the seventh bit, the 18^(th) bit, the 34^(th)bit, the 47^(th) bit, and the 56^(th) bit from the obscured deviceidentifier, resulting in the 8 byte device identifier.

At 908, the authentication device authenticates the tracking devicebased on the unobscured device identifier. In embodiments, theauthentication device may determine whether the unobscured deviceidentifier is a valid device identifier. As discussed, in someembodiments the authentication device maintains a list of known deviceidentifiers that indicates the device identifiers of all the trackingdevices that are able to be authenticated by the authenticating device.In these embodiments, the authentication device may cross reference theunobscured device identifier obtained from the decrypted transmitmessage with the list of known device identifiers to determine whetherthe device identifier appears in the list. If so, the authenticationdevice determines that the tracking device is authenticated. Otherwise,the authentication device determines that it cannot authenticate thedevice. Once a determination is made regarding the tracking device'sauthenticity, the authentication device may provide a notification to arelevant device or system.

In some embodiments, the authentication device may further ensure thatthe encrypted message or obscured device identifier has not beenpreviously received, prior to authenticating the device. In theseembodiments, the authentication device may maintain a list of previouslyreceived encrypted messages and/or obscure device identifiers. When arepeated encrypted message and/or obscured device identifier isreceived, the authentication device may determine that the encryptedmessage was previously intercepted by a malicious party and used tospoof a tracking device. In these scenarios, the authentication devicemay request that the tracking device resend a new encrypted message,such that the new message should change between transmissions due to thenew random N-bit string that was used to obscure the device identifierin the subsequent new encrypted message. In other embodiments, thetracking devices may send more than one (i.e., two or more) encryptedresponse messages, where each encrypted message is generated using adifferent random N-bit string. In these embodiments, the authenticationdevice may decrypt the multiple encrypted messages and may remove theN-bits using the same secret pattern from each obscured deviceidentifier to obtain the device identifier from each obscured deviceidentifier. If the obscured device identifiers vary while the obtaineddevice identifiers match, then the authentication device may thendetermine if the obtained device identifier is a known tracking deviceidentifier.

FIG. 10 illustrates an example bulk acoustic wave (BAW) oscillator 1000according to some embodiments of the present disclosure. In someembodiments, the BAW oscillator 1000 may be the oscillator of the firsttransmission module 310 of FIG. 3. In some embodiments of the passivetracking device 108, the BAW oscillator 1000 may be the oscillator ofFIG. 4. The BAW oscillator 1000 may be used as an oscillator in othersuitable tracking devices without departing from the scope of thepresent disclosure.

In some embodiments, the BAW oscillator 1000 is a monolithic CMOS-basedhigh-accuracy reference oscillator that is inexpensive to install intracking devices (e.g., multi-mode tracking devices 102, paired trackingdevices 106, passive tracking devices 108, and/or dual medium trackingdevices 112). These tracking devices may use a carrier signal having afrequency based on outputs of the BAW oscillator 1000 to achieve adesired accuracy of carrier frequency for transmission of signals. Inembodiments, the BAW oscillator 1000 includes a master clock 1002, atime difference detector 1004, a phase frequency detector 1006, and aloop filter 1008, which are described in greater detail below.

In embodiments, the master clock 1002 is a voltage-controlled oscillatorwhich is locked to delay time between the successive echoes. Inembodiments, the master clock 1002 may be a continuously runningoscillator of a frequency (F1) suitable for a clock burst function(e.g., a low GHz frequency). A clock burst may refer to a predefinednumber of consecutive clock bursts. The number of clock bursts can beselected so as the clock burst provides enough energy to pass through asubstrate of the tracking device with sufficient signal-to-noise ratio.In embodiments, the number of clock cycles is between 20 and 40. Inembodiments, the frequency F1 is an RF oscillator frequency that is alow GHz frequency (e.g., 1024 MHz). In embodiments, a counter driven bythis clock counts a set of master clock pulses and outputs a signalhaving peaks at a frequency corresponding to a rate of completed countsof the master clock pulses, which form the clock burst.

In embodiments, the time difference detector 1004 includes one or moreenvelope detectors (also referred to as echo detectors) driven by analuminum-nitrate (AlN) receive transducer. In some of these embodiments,an envelope detector is used to recover an envelope, i.e., a measurementof time between pulses, of first and second echoes of the clock burst.The first echo enables a counter that counts a fixed number N4 of themaster clock's cycles and then generates an end pulse. In embodiments, atemperature compensation signal is used to adjust the envelope detectorthresholds for the first and second echoes, as well as to control afractional N divider using, for example, dithering between multiple N4values.

In embodiments, the phase frequency detector 1006 compares the time ofthe second echo with the end pulse. If the end pulse arrives before thesecond echo, then the phase frequency detector 1006 generates a ‘pumpdown’ pulse, because the master clock is too fast. If the second echoarrives before the end pulse, the master clock is too slow, and a ‘pumpup’ pulse is produced. The pump-up and pump-down pulses drivecomplementary current sources, i.e., charge pumps, which in turn drive aloop filter 1008 that is connected to the control port of the masterclock VCO, thereby forming a frequency locked loop. The frequency lockedloop forces the frequency of the master clock to be a multiplicativeproduct of a count N1 and a reciprocal of the echo time, where N1 is amultiplicative product of F1 and a repetition rate of the ultrasonicpulse. This entire cycle is repeated regularly after several echo timeshave elapsed, for an overall recycle time in the hundreds ofnanoseconds. Finally, the locked master clock signal is divided byanother counter, e.g., N1, to result in the oscillator's output, astable reference clock frequency F2.

FIG. 11 illustrates example embodiments of the master clock 1002according to some embodiments of the present disclosure. In embodiments,the master clock 1002 is a precision clock that provides timing signals(i.e., a reference frequency) to synchronize a reference clock 1010,such as a clock included in the AC power source 407 of FIG. 4. Inembodiments, the master clock 1002 includes a voltage-controlledoscillator (VCO) 1102, a plurality of master clock counters 1104-1,1104-2, 1104-3 (generically referenced by 1104), one or more masterclock latches 1106, and one or more gates 1108. In embodiments, themaster clock 1002 is locked to a delay time. The delay time is a timebetween successive echoes of a bulk acoustic wave (BAW) resonator. Insome embodiments, the master clock 1002 receives input from thefree-running VCO 1102. In embodiments, the VCO 1102 is a ringoscillator. The master clock 1002 is tuned to the RF oscillatorfrequency, F1, by the VCO 1102. The frequency F1 may be a low-GHzfrequency suitable for a clock burst function. In some embodiments, theVCO 1102 is configured such that F1 that is substantially equal to 1024MHz.

In embodiments, the master clock counters 1104 are digital counters thatare each configured to store respective counts (e.g., counts N1-N3) thatindicate a number of times that a particular event or process hasoccurred. In some embodiments, one or more of the master clock counters1104 count oscillations of the VCO 1102. In some of these embodiments,the master clock counters 1104 are digital counters that may includelatches and/or flip-flops. In embodiments, the one or more master clockgates 1108 are digital logic gates that perform logical operations onthe counts received from the master clock counters 1104 to form a clockburst. In embodiments the one or more master clock gates 1108 include anAND gate. The AND gate receives a count signal, e.g., a signal frequencyof a factor of N1, and a frequency signal, e.g., a signal havingfrequency F1, and performs an AND operation on the count signal and thefrequency signal, thereby generating and outputting the clock burst. Inembodiments, the clock burst is a signal having a frequency equal to alogical AND value of a signal having peaks corresponding to a fractionalcount of a signal having the frequency F1, and a signal having thefrequency F1. In embodiments, the one or more master clock gates 1108output the clock burst to the time difference detector 1004. In someembodiments, the VCO 1102, and the one or more master clock counters1104 may be configured to output pulses, signals, and/or counts to theone or more master clock latches 1106, e.g., flip-flops, and the one ormore master clock latches 1106 may be configured to output signals orrefrain from outputting signals based on a cycle reset input.

FIG. 12 illustrates an example time difference detector 1004 accordingto some embodiments of the present disclosure. In embodiments, the timedifference detector 1004 is configured to receive clock bursts from themaster clock 1002, detect echoes of the BAW delay, and output echosignals, an end pulse, or a combination thereof to the phase differencedetector 1004. In embodiments, the time difference detector 1004includes a BAW delay reference 1202 (e.g., BAW delay 1202), a pluralityof echo detectors 1204-1, 1204-2 (also referred to as “envelopedetectors”), one or more time difference detector latches 1206, one ormore time difference detector gates 1208, one or more time differencedetector counters 1210, and a temperature compensation module 1212.

In embodiments, the BAW delay 1202 is configured to receive the clockburst from the master clock 1002 and output a BAW signal to the echodetectors 1204. Upon receiving the Clock burst, energy from the clockburst passes through a body of a silicon substrate of the BAW delay1202, thereby bouncing off of one or more edges of the silicon substrateand creating one or more echoes. The echoes are measurable in the BAWsignal, e.g., by measuring time between rising edges of the pulses ofthe BAW signal, and may differ according to temperature of the BAW delay1202.

In embodiments, the echo detectors 1204 are configured to receive theBAW signal and measure the time between the echoes (e.g., via envelopedetection). FIG. 12 illustrates an embodiment of the time differencedetector 1004 including two echo detectors 1204, wherein each echodetector 1204 measures a different echo of a plurality of echoes of theBAW delay 1202. In some embodiments, after measuring the time betweenthe echoes, each respective echo detector 1204 outputs a respective echosignals indicating a respective echo measurement to one or more timedifference detector latches 1206, one or more time difference detectorgates 1208, and/or one or more time difference detector counters 1210.

In embodiments, the time difference detector counter 1210 is a digitalcounter that is configured to store a count (e.g., a variable count N4)indicating a number of master clock cycles following the rising edge ofthe first echo. In some embodiments, the time difference detectorcounter 1210 issues an end pulse when the count reaches N4. Inembodiments, the count value N4 may be varied from one cycle to thenext, thereby affecting a fractional count value in the average acrossmultiple cycles. In embodiments, the time difference detector counters1210 are digital counters that may include latches or flip-flops. Insome embodiments, the time difference detector counter 1210 outputs theecho counts to the phase frequency detector 1006.

In some embodiments, a first echo detector 1204-1 of the plurality ofecho detectors 1204 detects a first echo of the BAW delay 1202 andtransmits a first echo signal to a time difference detector counter1210, wherein the first echo signal contains a metric of the first echo.A second echo detector 1204-2 of the plurality of echo detectors 1204may detect a second echo of the BAW delay 1202 and may generate a secondecho signal, wherein the second echo signal contains a metric of thesecond echo. The time difference detector counter 1210 is configured towork with the time difference detector latch 1206 and/or the timedifference detector gate 1208 to perform a logical AND operation on thefirst echo signal and pulses from the master clock 1002 to generate anend pulse, wherein the end pulse is a signal indicating that apredefined count N4 of master clock cycles has elapsed after the firstecho detect signal. The time difference detector 1004 outputs the endpulse and the second echo detect signal to the phase frequency detector1006.

In embodiments, a temperature compensation module 1212 is configured toreceive a temperature reading from a temperature sensor, e.g., a coarsetemperature reading from a bulk acoustic wave temperature sensor, andoutput temperature adjustment signals to the plurality of echo detectors1204 and/or the time difference detector counter 1210, wherein thetemperature adjustment signals are based on the temperature reading. Inembodiments, upon receiving the temperature adjustment signals from thetemperature compensation module 1212, the plurality of echo detectors1204 adjusts the echo detection based on the temperature adjustmentsignal and/or the time difference detector counter 1210 adjusts countssuch as the count N4 based on the temperature adjustment signal, therebyallowing the time difference detector 1004 to precisely and accuratelydetect and count echoes despite fluctuations in temperature of the BAWoscillator 1000. In some embodiments, the echo detectors 1204 areconfigured to adjust an echo detection threshold based on the respectivetemperature adjustment signals received from the temperaturecompensation module 1212. In some embodiments, the time differencedetector counters 1210 are configured to adjust a count, such asadjusting a fractional N divider using, for example, dithering betweenmultiple count values, based on the respective temperature adjustmentsignals received from the temperature compensation module 1212. Itshould be appreciated that while FIG. 12 illustrates a time differencedetector 1004 including two echo detectors 1204 wherein each echodetector 1204 measures a different echo of a plurality of echoes of theBAW delay 1202, some embodiments of the time difference detector 1004include a single echo detector 1204 wherein the single echo detector1204 measures a single echo of the BAW delay 1202.

FIG. 13 illustrates an exemplary embodiment of the phase frequencydetector 1006 and the loop filter 1008. In embodiments, the phasefrequency detector 1006 includes a phase frequency detection module 1302configured to receive the second echo signal and the end pulse from thetime difference detector 1004 and to generate a pump pulse basedthereon. The pump pulse may be either a “pump-down” pulse or a “pump-up”pulse, based upon a difference in time between the first and secondechoes. If the phase of the end pulse is earlier than the phase of thesecond echo signal, the master clock 1002 may be too fast, and the phasefrequency detection module 1302 generates a pump-down pulse. If thephase of the end pulse is later than the phase of the second echosignal, the master clock 1002 may be too slow, and the phase frequencydetection module 1302 generates a pump-up pulse.

In embodiments, the phase frequency detector 1006 includes complementarycurrent sources 1304, 1306 (e.g., charge pumps). The phase frequencydetection module 1302 outputs the pump-down pulse or the pump-up pulseto the complementary current sources 1304, 1306. The complementarycurrent sources 1304, 1306 selectively output a current to the loopfilter 1008 based on whether a pump-down pulse or a pump-up pulse wasreceived from the phase frequency detection module 1302. If a pump-downpulse was received from the phase frequency detection module 1302 anegative current source 1304 of the complementary current sources 1304,1306 transmits a negative current to the loop filter 1008. If a pump-uppulse was received from the phase frequency detection module 1302, apositive current source 1306 of the complementary current sources 1304,1306 transmits a positive current to the loop filter 1008.

In embodiments, the loop filter 1008 includes a loop amplifier 1308. Theloop amplifier 1308 is configured to amplify the current received fromthe negative current source 1304 or the positive current source 1306,and output the amplified current to an input of the VCO 1102 of themaster clock, thereby forming a feedback loop and decreasing orincreasing the output frequency of the BAW oscillator 1000 based uponthe pump-down pulse or the pump-up pulse. In some embodiments, the loopamplifier 1308 is a third-order type 2 phase-locked loop.

FIGS. 14-17 illustrate example variations of the bulk acoustic waveoscillator 1000 according to different embodiments of the presentdisclosure.

In the example of FIG. 14, the master clock of the BAW oscillator 1000operates as a burst clock at burst frequency. In this example, a countercounts the clock cycles from the start of the clock burst transmissionto the start of the first received echo of the clock burst. In thisexample, the BAW oscillator 1000 compares the terminal count with thetiming of the first echo, without considering a second echo.

In the example of FIG. 15, a separate ring oscillator is bursted on fora duration (e.g., 30 ns) by the master clock, which operates at, forexample, 1/176 ns, or 5.68 MHz. The leading edge of the next masterclock cycle is compared with the first echo pulse, without considering asecond echo.

In the example of FIG. 16, the master clock operates as a burst clock atburst frequency. In this example, the first echo enables the counter tocount the clock cycles until a number, i.e., a count, of clocks havepassed (e.g., 180 clocks have passed). In this example, the BAWoscillator 1000 compares the terminal count with the edge of the secondecho. A second phase-frequency detector is used to track a phaseambiguity when the counter is enabled (e.g., +/−half of a master clockcycle).

In the example of FIG. 17, a separate ring oscillator is bursted by themaster clock, as in FIG. 15. In this example, the master clock frequencycan now be a relatively lower multiple of the 5.68 MHz, even as low as 1MHz. In this case, the counter can be removed entirely. Alternatively, a‘moderately’ low master clock frequency of 2, 3, 4, 5, or more times5.68 MHz can be used, and then a counter of this size may be required.

FIG. 18 illustrates an example configuration of a passive trackingdevice 108 according to some embodiments of the present disclosure. Thepassive tracking device may include a low-power encryption module, oneor more sensors, a state machine, non-volatile memory (NVRAM), a voltageregulator, resonator, an integer synthesizer, an oscillator (e.g., a BAWoscillator), a charge pump, and a demand module. The passive trackingdevice 108 may further include capacitors, one or more antennas, one ormore inverters, and other suitable components.

FIG. 19 illustrates an example aggregator device 104 according to someembodiments of the present disclosure. In embodiments, an aggregatordevice 104 may include a processing device 2102, one or more longdistance communication units 2104 (WIFI chip, an LTE chip, an EthernetCard, and the like), one or more short distance communication units 2106(RFID chipset, Bluetooth Chipset, and the like), a GPS device 2108, apower supply 2110 (e.g., continuous power supply, a rechargeablebattery, an inductive power supply, and/or the like), one or moreenvironmental sensors 2112 (e.g., thermistors, thermometers, pressuresensors, ambient light sensors, accelerometers, gyroscopes, videocameras, IR cameras, and the like), one or more storage devices 2114(e.g., RAM, ROM, Flash memory, and the like), and an internal clock2116.

In embodiments, the long distance communication units 2104 effectuatecommunication with a communication network (e.g., the Internet, acellular network, and the like). The processing device 2102 can transmitmessages to external devices, such as the backend server 120 via thelong distance communication units. In embodiments, the long distancecommunication units 2104 may be configured to receive messagescontaining tracking information and any other suitable information fromtracking devices having requisite communication capabilities (e.g., viaWIFI).

A short distance communication unit 2106 may effectuate short distancecommunication with tracking devices (e.g., multi-purpose trackingdevices 102, paired tracking devices 106, passive tracking devices 108,dual-mode tracking devices 112, and exciters 102). In embodiments, ashort distance communication unit 2106 may broadcast signals to energizeproximate devices or otherwise trigger reporting by a proximate device.The short distance communication unit 2106 may receive return signals(or “response signals”) from devices that contain short messages thatmay include tracking information and/or any other suitable data (e.g.,sensor readings).

In some embodiments, the short distance communication units 2102 includeone or more multiple-out-multiple-in (MOMI) devices. FIG. 20 illustratesan example MOMI device 2200. In embodiments, a MOMI device 2200 includesone or more MOMI transceivers 2202 that each includes two or moreantennas 2204 spaced in relative proximity to one another (e.g., <20 cm)that are set at an angle from one another (e.g., between 60 degrees and120 degrees). A MOMI device 2200 may further include signal processingcircuitry 2206 (e.g., an R/F analog front end 2212, ADC and DACconverters 2210, FGPAs 2208, and the like) that controls, modulates,converts, and/or filters analog signals and digital signals (as shown inFIG. 20). In embodiments, a MOMI device 2200 may modulate RF signalsfrom the MOMI transceiver 2202 that energize any proximate trackingdevices, which in turn provide a response RF signal (or responsesignal), which may be a weaker signal. The response signals may containmessages that include tracking information (e.g., a tracking device ID)of the energized tracking device. The MOMI device 2200 routes theresponse RF signal to the processing device 2102, which may use thetracking information encoded therein to identify messages received fromdifferent tracking devices.

In embodiments, the MOMI device 2200 can determine a range and bearingof the energized tracking device with respect to the MOMI device 2200using response signals received from an energized tracking device (e.g.,passive tracking devices 108,112), which is described in greater detailbelow. A range may be a value that indicates a distance between the MOMIdevice 2200 and the energized tracking device. A bearing may be a valuethat indicates an orientation of the energized tracking device and theMOMI device 2200 (e.g., an angle between a reference vector and adirection vector from the MOMI device 2200 to the energized trackingdevice). The MOMI device 2200 may output determined range and bearingvalues to the processing device 2102.

An example method of operating the MOMI device 2200 according to someembodiments of the present disclosure is now described in greaterdetail. In embodiments, a controller sends a command to the modulatorsignal processing block, where the command is to initiate an energizingtransmission. The modulator block creates a digitized baseband signal tosend to the digital to analog converter. The digitized signal isconverted to an analog signal, filtered, and up-converted from basebandto the RF frequency which will be used to transmit over the air. Inembodiments, the RF signal may be amplified in the power amplifier(e.g., to 33 dBm or 2 Watts). The amplified signal may be split into twoor more equal power signals and sent to two or more respective couplers.Each coupler routes a transmit signal from the transmitter path to arespective antenna 2204 of the MOMI transceiver 2202, and also routesthe receive signal (also referred to as a “response signal”) from therespective antenna 2204 to the receiver path. In some embodiments, eachcoupler is connected to a switch that connects to a respective antenna2204. In embodiments, each of the split signals are transmitted from apair of equal gain antennas, which are collocated but pointing inslightly different direction, for example between 60 and 120 degreesapart. In embodiments, the MOMI device 2200 may have multiple MOMItransceivers 2202 to create multiple non-simultaneous read zones usingthe switches.

In response to RF signals from a MOMI transceiver 2202, tracking devicesin the read zone of the MOMI transceiver 2202 respond to RF commandsfrom the MOMI device 2200 by, for example, backscattering itsidentification number (e.g., tracking device ID) on a subcarrier, forexample 160 KHz from the main carrier. In most cases, the response levelof energized tracking device is closer to the boresight of one antenna2204 and will be much stronger on that antenna. If the energizedtracking device is halfway between the boresights of the two antennas,the response level will be effectively equal. Thus, the MOMI device 2200may estimate an angle that a tag lies between the boresights of the twoantennas 2204 based on the response level measured from each antenna2204. The variation in signal level will be a function of the antennagain vs angle. In embodiments, the angle estimation can be calibratedfor a given antenna pair either a priori or real time using camerainputs.

The response backscatter signals transmitted by the energized trackingdevice are received by each antenna 2204 of the MOMI transceiver 2202and routed back through the respective switches and couplers. Thereceive signal from each antenna 2204 of the MOMI transceiver 2202 maybe amplified by a low noise amplifier and down-converted to complexin-phase (I) and quadrature (Q) rails. The I and Q analog signals may below pass filtered and converted to digital samples by an analog todigital converter. In embodiments, each I and Q signal pair is processedseparately in a demodulator signal processing block. In embodiments,processed output from one demodulator may be used to improve theprocessing in the other demodulator. Each demodulator extracts thetracking information from the response signal if there is sufficientsignal to noise ratio to do so. Each demodulator also extracts receivesignal strength information (RSSI) and the phase difference of arrival(PDOA) of the return signal relative to the transmit signal carrierphase. The RSSI and PDOA from each demodulator block is used tocalculate the bearing and range estimates. Before every transmit, theMOMI device 2200 may perform a carrier cancellation procedure tominimize the leakage of the strong transmit signal, e.g., 30 dBm, backto the receiver to improve receiver sensitivity to low level, e.g., −80dBm tag response signals. In embodiments, the MOMI device 2200 mayimplement a link budget equation.

The foregoing is an example implementation of a MOMI device 2200 andother implementations of a MOMI device 2200 are contemplated and withinthe scope of the disclosure.

Referring back to FIG. 19, in embodiments the processing device 2102 mayinclude one or more processors that execute executable instructions. Inembodiments, the processing device is a multi-core mobile processorhaving a neural processing engine. In embodiments, the processing device2102 may execute and/or include a tracking system 2130, a monitoringsystem 2132, a machine vision module 2134, a machine learning module2136, and a reporting module 2138. These modules may be implemented asexecutable instructions, circuits, and/or hardware components. Theprocessing device may execute or include additional or alternativemodules without departing from the scope of the disclosure.

In embodiments, the tracking module 2130 tracks items in the proximityof the aggregator device 104. In embodiments, the tracking module 2130may initiate the broadcasting of an output signal that may energizepassive tracking devices 108, 112, or otherwise trigger reporting byother tracking devices 102, 106 in the vicinity of the aggregator device104. In some embodiments, the energizing signal may include a command toreport tracking data (and any other suitable data). The tracking module2130 may track items based on short messages that are transmitted fromrespective tracking devices 102, 106, 108, and/or 112 that received theoutput signal. In response to receiving a short message from a trackingdevice, the tracking module 2130 may read the tracking information ofthe transmitting device (e.g., the tracking device ID), and any otherrelevant data that was provided in the short message (e.g., temperaturedata, ambient light data, humidity data, time stamps, and the like). Insome embodiments, the tracking module 2130 may decrypt a short messagereceived from a respective tracking device. For example, the trackingmodule 2130 in accordance with the method described above. The trackingmodule 2130 may dedupe short messages if multiple instances of a shortmessage are received by the tracking module 2130.

In embodiments, the tracking module 2130 may receive trackinginformation from the machine vision module 2134. In these embodiments,the machine vision module 2134 may read a visual indicia captured by acamera of the aggregator device or a camera that streams video to theaggregator device 104. In some of these embodiments, the value in thevisual indicia may be the same value as the tracking device ID that isassigned to a tracking device, such that the visual indicia and thetracking device may track the same item. In these embodiments, thetracking module 2130 may dedupe two separate tracking events (i.e., onefrom a tracking device and the other from a visual indicia), so as notto double report an item.

In embodiments, the tracking module 2130 may, for each unique trackingevent, generate a tracking event record that records the tracking event.Examples of tracking events may include the receipt of a message from atracking device and/or reading tracking information from a visualindicia by the machine vision module 2134. In these embodiments, atracking event record may be any suitable data structure that includesdata relating to a tracking event. A respective tracking event recordmay include, but is not limited to, a device identifier of the trackingdevice that provided the message or that was read from a visual indicia,a geolocation corresponding to the tracking device (or item), and a timestamp. The geolocation may be reported by the tracking device (e.g.,tracking devices 102 or 106) or may be obtained by the tracking module2130 from the GPS device 2108 of the aggregator device when thereporting tracking device does not have GPS or other location-basedfunctionality. In some embodiments, the geolocation may be determinedbased on the GPS reading from the GPS device 2108 and refined based onthe range and bearing values determined by a MOMI device 2200. In theseembodiments, the geolocation of an individual item may be betterestimated than merely using the geolocation of the aggregator device104. The time-stamp may be reported by the tracking device or may beobtained from the clock 2116. In embodiments, the tracking module 2130may include other data in a tracking event record, such as sensormeasurements obtained in a message and/or read from the environmentsensors 2112. The tracking module 2130 may output a tracking eventrecord to the reporting module 2138 and/or may write the tracking eventrecord to the storage device 2114. Additionally or alternatively, thetracking module 2130 may maintain data logs, such as tracking logs,temperature logs, light logs, ambient pressure logs, and the like. Thetracking module 2130 may write these data logs to the storage device2114, where the data logs are reported to a backend server 120 (oranother suitable device) by the reporting module 2138.

In embodiments, the monitoring system 2132 monitors one or moreconditions to determine the existence of an incident. An incident may beany condition that is deemed to be notable (e.g., by an expert and/orlearned from training data sets that includes training data setsrelating to incidents and training data sets relating to non-incidents).In some embodiments, the monitoring system 2132 may apply rules-basedlogic to determine if one or more conditions are met that trigger anenvironmental incident. In embodiments, the monitoring system 2132 maymonitor the environment of the aggregator device 104 to determine ifthere are any environmental incidents (e.g., the temperature is too highor too cold, the humidity is too high, etc.). In these embodiments, themonitoring system 2132 may leverage the machine learning module 2136 toobtain classifications or predictions regarding the environment, such astrends in the sensor data that may indicate that an environmentalincident has been triggered (classification) or likely to be triggered(prediction). In these embodiments, the monitoring system 2132 mayprovide sensor data to the machine learning module 2136, which leveragesone or more classification models trained to classify environmentalincidents and/or one or more prediction models trained to predictwhether an environmental incident is likely based on the sensor data. Inthe event the monitoring system 2132 determines that there is anenvironmental incident or one is likely, the monitoring system 2132 maygenerate an incident record. In these embodiments, the incident reportmay include the type of incident (e.g., the type of environmentalincident) that was determined, classified, or predicted, the data thatwas read to determine, classify, or predict the incident, and atimestamp.

In embodiments, the monitoring system 2132 may monitor one or more itemsto determine if a label having visual indicia or a tracking device hasbeen missing, damaged, or otherwise not readable or not reporting. Inthese embodiments, the monitoring system 2132 may receive input from themachine vision module 2134 and/or the tracking module 2130 to determineif a visual indicia or tracking device has been missing, damaged, orotherwise unreadable or not reporting. In some embodiments, themonitoring system 2132 may receive tracking data from the trackingmodule 2130 and a value read from a visual indicia from the machinevision module 2134. If the monitoring system 2132 receives a value butdoes not receive corresponding tracking data, the monitoring system 2132may determine that the item associated with a value does not have atracking device or the tracking device is not responding. Similarly, ifthe monitoring system 2132 does not receive tracking data from thetracking module 2130, but does receive a value from the machine visionmodule 2134, the monitoring system 2132 may determine that the itemassociated with a value does not have a tracking device or the trackingdevice is not responding. In some embodiments, the monitoring system2132 may receive reports from the machine vision module 2134 thatindicate when a trackable item (e.g., an item that should have atracking device or visual indicia affixed thereto) is in the field ofview of a camera in communication with the machine vision module 2134.In some of these embodiments, the machine vision module 2134 may furtherprovide an estimated distance of the item from the aggregator device(e.g., based on 3D video that includes depth data and a calibrationbetween the camera and the aggregator device). When the monitoringsystem 2132 does not receive tracking information and the estimateddistance is less than the read range of the aggregator device 104, themonitoring system 2132 may determine that the tracking devicecorresponding to the item is missing, damaged, or otherwise notreporting. Furthermore, if the machine vision module 2134 detects atracking device affixed to the detected item (e.g., using an imageclassifier), the machine vision module 2134 can determine that thetracking device is damaged or otherwise malfunctioning. In response todetermining that a tracking device is missing, damaged, malfunctioning,or otherwise not readable, the monitoring system 2132 may generate anincident record that is reported to the reporting module 2138 and/orstored in the storage device 2114.

In embodiments, the monitoring system 2132 receives reports of damageditems from the machine vision module 2134. In these scenarios, themonitoring system 2132 may obtain tracking data from the tracking module2130 and/or from the machine vision module 2134 (i.e., a scanned value).The monitoring system 2132 may generate an incident record thatindicates a damaged item event and the tracking data (e.g., a trackingdevice ID) associated with the damaged item. In embodiments, themonitoring system 2132 may include additional data in the incidentrecord, such as an image of the damaged item. The monitoring system 2132may report the incident record the reporting module 2138 and/or storethe incident record in the storage device 2114.

In embodiments, a machine vision module 2134 receives camera signalsfrom one or more cameras of the aggregator device 104 and/or from one ormore external cameras of a vision system 116 that stream camera signalsthereto. In these embodiments, the cameras may include, but are notlimited to, hi-res video cameras, depth cameras, IR cameras, and/or 3Dcameras, and the camera signals may include but are not limited to videosignals, depth signals, IR signals, and/or 3D video signals (which mayinclude video data and depth data), and the like.

In some embodiments, the machine vision module 2134 may include one ormore image classifiers that are trained to detect one or more conditionsbased on one or more frames of a camera signal. The image classifiersmay be trained to identify trackable items (e.g., trained to identifyboxes, specific products, bags, pallets, and the like), items that mayhave been damaged, visual indicia that are affixed to on an exteriorsurface of an item, and/or tracking devices that are affixed to on anexterior surface of an item. For example, image classifiers may betrained on images containing items that should be tracked (and imagesthat do not depict any items that should be tracked), images depictingitems that have been labeled damaged (and images depicting items thathave been labeled as “not damaged”), images depicting items having atracking device/visual indicia affixed to an outer surface thereof (andimages depicting items that do not have a tracking device/visual indiciaaffixed to a non-occluded outer surface thereof). Image classifiers mayimplement any suitable techniques, such as performing feature extractionon images, clustering (e.g., k-means clustering, KNN clustering, and thelike) the features of an image with features of labeled images,leveraging image classification models (e.g., one or more of varioustypes of neural networks, regression models, etc.), and the like.

In some embodiments, when a classifier classifies an image as depictinga trackable item (e.g., an item that should have a tracking deviceand/or a visual indicia affixed thereto), the machine vision module 2134may report the detection of the item to the monitoring system 2132,regardless of whether or not a tracking device or visual indicia isaffixed thereto. Such reporting may serve as notice that an item thatshould be tracked is in the vicinity of the aggregator device 104.

In some embodiments, when a classifier classifies an image as depictinga visual indicia, the machine vision module 2134 may scan and decode thevisual indicia to obtain the value encoded in the visual indicia. Insome of these embodiments, the machine vision module 2134 may beimplemented with or may communicate with a decoder that decodes thescanned visual indicia (e.g., a bar code decoder or a QR-code decoder).The machine vision module 2134 may output a report of the detection ofthe visual indicia to the monitoring system 2132 and/or may report thevalue encoded therein to the tracking module 2130.

In some embodiments, when an image classifier classifies an image asdepicting an item that has a tracking device affixed thereto, themachine vision module 2134 may report the detection of the trackingdevice to the monitoring system 2132. In this way, the monitoring system2132 may determine whether the tracking device is operating properly, asit should receive tracking data from the detected tracking device.

In some embodiments, when an image classifier classifies an image asdepicting a damaged item, the machine vision module 2134 may report thedetection of the damaged item to the monitoring system 2132. In some ofthese embodiments, the image classifier may be trained with labeled setsof training data that include images of items and labels indicatingwhether the items depicted in the images were damaged or undamaged.During training, the features of these respective images may beextracted and combined with the label (damaged or undamaged) ascribed tothe respective image. In some of these embodiments, the labels mayindicate the type of damage (e.g., broken seal, ripped packaging, openedpackaging, etc.), such that the image classifier may classify the typeof damage that is detected. In embodiments, the report may indicate thetracking information corresponding to the tracking device that isassociated with the damaged, and in some of these embodiments, the typeof damage.

In some embodiments, the machine vision module 2134 may perform videoprocessing/analysis on the received camera signals. In some of theseembodiments, the machine vision module 2134 may be configured todetermine a distance between a detected item and the aggregator device104. In some of these embodiments, the vision module 2134 may beconfigured to receive 3D video streams that include video and depthdata. In these embodiments, the 3D video may be analyzed to determine anestimated distance between the camera and a detected item. The machinevision module 2134 may use this value to determine a distance betweenthe item and the aggregator device 104 based on a calibration betweenthe video camera and the aggregator device 104. In some embodiments, thevideo may be analyzed to determine a size of a detected item, based onfor example the location of the detected item in a frame of the videoand an intrinsic calibration of the camera that captured the video.

In some embodiments, the machine vision module 2134 may receive rangeand bearing values determined by a short range communication unit 2106(e.g., MOMI device of FIG. 20), such that each set of range and bearingvalues is associated with the tracking information of the trackingdevice to which the range and bearing values pertain. The range andbearing values may indicate a distance of a tracking device from theaggregator device 104 (and therefore a distance of the item beingtracked), and the range may indicate an orientation with respect to theaggregator device 104 (e.g., an angle with respect to a reference linecorresponding to the aggregator device 104). In some embodiments, themachine vision module 2134 (or the monitoring system 2132 or thetracking module 2130) may use the range and bearing values along withimage classifications to disambiguate two or more items when trackinginformation is received for two or more items and two or more items areobserved in a video frame. In these embodiments, the aggregator device104 may be calibrated with each camera, which provides the machinevision module 2134 with an orientation of the aggregator device 104 withrespect to the field of view of the camera. Thus, the aggregator device104 may determine which item corresponds to a particular tracking devicebased on the range and bearing pertaining to the particular trackingdevice and a video frame that depicts two or more items. In theseembodiments, the ability to disambiguate multiple items that aretransmitting tracking information provides the aggregator device 104with improved reliability and cross-validation of tracking data. Forexample, if a particular item is classified as damaged, the machinevision module 2134 may identify the tracking information of the damageditem when there are multiple items to choose from.

In embodiments, a machine learning module 2136 performs machine learningand artificial tasks on behalf of the aggregator device 104. In someembodiments, the machine learning module 2136 may implement theTensorFlow library. In embodiments, the machine learning module 2136 maytrain models that are used by the aggregator device 104. Additionally oralternatively, the machine learning module 2136 may obtain trainedmodels from a backend server 120 that trains models based on expertgenerated training data sets and/or training data sets that are receivedfrom one or more aggregator devices 104. In these embodiments, thebackend server 120 may maintain a library of models that can be used forvarious artificial intelligence-based tasks. In embodiments, machinelearned models may include neural networks (e.g., recurrent neuralnetworks, convolutional neural networks, deep neural networks),regression based models, Hidden Markov models, Bayesian models, decisiontrees, and the like. In embodiments, these machine learned models mayinclude models of deployment configurations that may be used toconfigure the aggregator device 104. The models may additionally oralternatively include image classification models, environmentprediction models, environment classification models, and the like.

In embodiments, the machine learning module 2136 may use inputs from thetracking devices, such as the tracking information and range and bearingvalues, and/or input from a camera (e.g., 3D camera) to train and/orleverage models that are used to configure the aggregator to accuratelyread and disambiguate items that are being tracked. In embodiments, themachine learning module 2136 may further use GPS, cellular data, and/orWIFI data to auto-configure the aggregator device 104.

In some embodiments, the machine learning module 2136 may leverageclassification or prediction models that are trained to classify orpredict changes in the environment of the aggregator device 104 and/orchanges in the sensors of the aggregator device 104. In theseembodiments, the machine learning module 2136 may obtain sensor datafrom the environmental sensors 2112 and/or from tracking devices and mayinput the sensors data to classification models and/or prediction modelsto determine changes in the environment or the sensors 2112 of theaggregator device 104. Furthermore in embodiments, the machine learningmodule 2136 may use outcomes associated with those predictions orclassifications (e.g., user provided outcomes) to reinforce/retrain themodels.

In embodiments, the machine learning module 2136 may leverage modelsand/or a set of rules to improve accuracy of error handling. Exceptionsare conditions that have been previously classified as being normal.Examples of exceptions include misreading of tracking data and/or visualindicia, ambiguity regarding an identification (e.g., two packages aretouching one another), and/or a package is only slightly damaged. Inembodiments, the machine learning module 2136 may execute aclassification algorithm that feeds into a rules-based exceptionhandler. These rules may be hard coded by a developer and/or may belearned based on analytics. For example, the machine learning module2136 may record how one or more humans handle certain exceptions, suchthat the machine learning module 2136 (or a backend system 120) maylearn the rules for handling exceptions based on the human activity.

In embodiments, the machine learning module 2136 may be configured todetect changes in the RF environment of the aggregator device and tocompare the changes against a knowledge base of known changes. In theseembodiments, the machine learning module 2136 may sample frequencies andsignal strengths in the environment of the aggregator device and mayanalyze the sampled frequencies to determine if there is a change in theRF environment (e.g., signals that were always detected in the signalnoise are no longer being detected). In some of these embodiments, themachine learning module 2136 may compare these changes against aknowledge base of signal samples and signal sample trends to diagnosethe cause of the change.

The machine learning module 2136 may be used to perform additional oralternative machine learning tasks in connection with an environmentbeing tracked. These tasks may be domain-specific, as certain trackingfeatures (e.g., monitoring consumer engagement in a retail segment)require different types of models and algorithms than others (e.g.,monitoring packages in a shipping facility).

In some embodiments, the machine learning module 2136 may operate withthe backend server to optimize communications with the backend server120. In these embodiments, the machine learning module 2136 may useprediction models to predict the optimal time to transmit individual orbatches of tracking records and/or data logs, such that the predictionmodel is trained to determine when the backend server will consume saiddata.

In embodiments, the reporting module 2138 reports data to an externaldevice (e.g., a backend server 120 and/or a computing infrastructure ofa business entity). In embodiments, the reporting module 2138 mayreceive tracking event records from the tracking module 2130 and mayforward the tracking event records to an external device via the longrange communication unit 2104. In embodiments, the reporting module 2138may report tracking records in batches. In some of these embodiments,the reporting module 2138 may maintain a cache that stores the trackingevent records, such that the reporting module 2138 may periodicallybatch report the tracking event records in the cache to an externaldevice. In some embodiments, the tracking event records are stored inthe storage device 2112, such that the reporting module 2138periodically retrieves a batch of tracking event records, and reportsthe batch of tracking event records to an external device. The reportingmodule 2138 may report a batch of tracking event records at the requestof the external device (e.g., in response to receiving a request toreport unreported tracking event records), at predetermined times (e.g.,every ten minutes), or in response to a triggering condition (e.g., thecache is full).

In embodiments, the reporting module 2138 may report other data as well.For example, the reporting module 2138 may report data logs to anexternal device (e.g., backend server 120 or a computing infrastructureof a business entity). In other embodiments, the reporting module 2138may report incident records. In these embodiments, the reporting module2138 may receive the incident record from the monitoring system 2132 andmay transmit the incident record to an external device and/or may bereported as a notification to a specific person or set of people.

In embodiments, the reporting module 2138 may report data to a roboticssystem that is in communication with the aggregator device. For example,in automated shipping facilities the reporting module 2138 may receivesensor measurements from the environmental sensors 2112 and/or fromreporting tracking devices and may transmit environmental sensor data tothe robotics system, which may then take appropriate action based on thesensor data (e.g., shut down the line in response or adjust anenvironment condition in response to sensor data that is indicative ofan adverse condition). In these embodiments, the reporting module 2138may report additional or alternative data to a robotics system. Forexample the reporting module 2138 may report incident records, datalogs, and/or tracking event records to the robotics system.

The aggregator device 104 may include additional or alternativecomponents not discussed herein. For example in some embodiments theaggregator device 104 may be configured to detect the presence ofdisplay devices (e.g., smart monitors, smart televisions, wearabledevices, or mobile devices) and to connect to the local display devices.In these embodiments, the aggregator device 104 may be configured toload balance and assign work orders to the local display devices.

Referring back to FIG. 1, the aggregator devices 104 may be placed indifferent types of settings. These settings include manufacturingfacilities, shipping vehicles, shipping facilities, warehouses, deliveryvehicles, and retails settings. Depending on the setting, the aggregatordevice 104 may perform different functions. For example, in a shippingfacility setting, an aggregator device may ingest video (e.g., 3D video)from one or more cameras that monitor a conveyer belt that routespackages. The aggregator device 104 may read tracking devices and/orvisual indicia of packages, and may determine range and bearing ofpackage. The aggregator device 104 may use this information to routepackages, track packages, and/or identify damaged packages or trackingdevices.

In embodiments, an aggregator device 104 may be placed in a retailsetting, whereby the aggregator 104 may track the location of items inthe retail setting. In these embodiments, as consumers shop in thestore, they may be carrying user devices that report their respectivelocations and/or are trackable by the aggregator device 104 (by forexample a module in the operating system of the user device). In thisway, the aggregator device 104 or the backend server system 120 may beable to determine which items are looked at the most, which areas in thestore receive the most traffic, and the like.

In embodiments, the tracking system 100 may communicate with the backendserver system 120 via a communication network 190 (e.g., the Internetand/or a cellular network). The tracking system 100 may communicatelocation data to the backend server system 120 that indicates ageolocation and/or approximate locations of the one or more devices ofthe tracking system 100. For example, the tracking system 100 maycommunicate location data to the backend server system 120 that isobtained by a multi-mode tracking device 102 or a paired tracking device106 based on the GPS signal received by the device or a triangulationcalculation based on signal strengths of received electromagneticsignals (e.g., WIFI signals and/or cellular signals). In anotherexample, the tracking system 100 may communicate beacons collected frompassive tracking devices 108 to the backend server system 120. In thisexample, the backend server system 120 or another tracking device (e.g.,aggregator device 104 or multi-mode tracking device 102) can estimate alocation of a respective passive tracking device 108 based on thereceipt of a beacon (e.g., a device ID of the passive tracking device108) from a tracking device and a known location of the tracking device(e.g., obtained from a GPS signal or triangulation techniques). Thetracking system 100 may communicate additional types of data, as wasdescribed above. For example, the tracking system 100 may one or more ofcommunicate time stamps corresponding to when a particular data item wassampled, temperature data, ambient light data, humidity data, motiondata and the like.

The backend server system 120 may receive the location data temperaturedata, time stamps, ambient light data, humidity data, motion data and/orother suitable types of data and may perform any variety of operationsbased thereon. In embodiments, the backend server system 120 isconfigured to support inventory tracking. For example, the backendserver system 120 can verify that no inventory is currently missing froma shipment of goods. Additionally or alternatively, the backend serversystem 120 may be configured to manage the movement of items,checking-out of items, checking-in of items, or other similar actionsperformed with respect to items from a group of items (e.g., storedmedical supplies). In embodiments, the backend server system 120 isconfigured to maintain logs and/or databases corresponding to datacollected from tracking systems that track groups of items. For example,the backend server system 120 may maintain an index or log of locationdata, temperature data, ambient light data, humidity data, motion data,and/or other suitable types of data. In embodiments, the backend serversystem 120 is configured to support applications executing on a userdevice 130 and/or an AR-enabled user device 140, as is described below.In embodiments, the backend server system 120 may manage individualdevices in a tracking system 100. For example, the backend server system120 is configured to command an exciter 110 or an aggregator 104 tosample data from the other devices in the tracking system 100. Inembodiments, the backend server system 120 is configured to authenticatedevices in the tracking system 100, as was discussed above.

In combination, the tracking system 100 and the backend server system120 may support a number of different applications. The combination maybe configured to track inventory or items at facilities, to trackshipments of goods (e.g., food, medical supplies, and electronic goods),to support user device and/or AR-enabled user devices, and the like.Different applications of the combination of the tracking system 100 andthe backend server system 120 are discussed in greater detail below.

Medical supplies are expensive and keeping inventory may be difficultduring times of emergency. The same holds true for other industries,such as high tech test equipment and tools, jewelry, and the like. Insome applications, the tracking system 100 may be used to trackinventories of medical supplies (e.g., medical devices and/orpharmaceuticals) and other high value items. For example, in someembodiments, the passive tracking devices 108 (and/or the multi-modetracking device 102 and/or the paired tracking devices 106) areconfigured such that they can be read by commercially available userdevices (e.g., smartphones, tablets, scanners, and the like). Thetracking system 100 may be used to make supply room location, checkout,and inventory processes more efficient and reliable.

In embodiments, passive tracking devices 108 be applied to all supplyitems and in badges of employees. The user device 120 may run anapplication (native or web-application) that is configured to search forspecific items. In these embodiments, the application may adjust thetransmit power output by the user device 120 to reduce the search areafor localization. For example, the application may adjust the transmitpower such that the range of the user device 120 is less than fivemeters. The application and/or backend server system 120 may utilize alist of device IDs that correspond to specific passive tracking devices108 (and/or the multi-mode tracking device 102 and/or the pairedtracking devices 106), where each device ID may be correlated to aparticular item or employee. In this way, the application can read thedevice IDs of devices in the vicinity of the user device 130 to identifyitems that are in the vicinity. The application may also be provided anidentifier of a particular item, whereby the application can determinewhether the particular item is in the vicinity of the user device 130.Once the particular item is confirmed as in the vicinity, theapplication and/or a gateway device can check out the item and note theemployee badge ID.

In some embodiments, the application can control the user device 130 tochange a transmitter power of the user device 130 and/or theinterrogation rate depending on the proximity to a passive trackingdevice.

In some embodiments, each passive tracking device 108 may have a twoID's associated therewith: (i) an unencrypted model number or SKU ID;and (ii) an encrypted serialized device ID. The unencrypted ID may beused for searching for a particular item, while the encrypted ID may beused for item inventory management.

In some embodiments, all personnel user devices 130 may be configuredwith a custom application that reports the location (or approximatelocation) of any item beacons that the application detects while theuser device 130 and/or the item is in motion. The application may sendthe data to a backend server system 120, which can maintain a locationdatabase of all items whether stationary or moving.

In some embodiments, a tracker (e.g., an aggregator 104 or multi-modedevice 102 having an exciter 110) may be placed at each entry/exitgateway or hallway. The tracker may be configured to report the deviceIDs of each passive tracking device 108 it detects. It is noted that atracker may be said to have detected a passive tracking device 108 uponreceiving a beacon that contains a device ID of a particular passivetracking device 108 (which may be associated with an item or anemployee). The tracker may report the device ID, a time stampcorresponding to a time at which the device was detected, and/or alocation of the tracker when it detected the passive tracking device108. The tracker may send this data to a backend server system 120,which may maintain a location database of all items that are movingthroughout an area (e.g., hospital).

In some embodiments, a tracking system 100 may be used to track items ina personal space of a user (e.g., in a home). Most items in a person'sspace are not wirelessly visible because it is too expensive to put RFtags on most things. Low cost passive tracking devices 108 can increasethe number of tagged items such that they are much more prevalent.However, reading these tags may require some changes to how a userdevice 130 operates. Also, new applications and cloud-based services maybe required.

In some embodiments, a user device (e.g., smartphone or tablet) may beconfigured to emit RF power in order to power the passive trackingdevices 108 before listening for BLE beacons sent from the passivetracking devices 108. The user device 130 can be optimized for poweringthe passive tracking devices 108.

In some embodiments, the user device 130 may execute an application thatis configured to identify (e.g., “sniff”) all the passive trackingdevices 108 in the vicinity of the user device and to send a list of thedevice IDs of the identified passive tracking devices 108 to a backendserver system 120. Other information such as a location of the userdevice 130, detected WiFi networks, and the like can help locate thetagged items. The application/backend server system 120 may utilize alist of device IDs that correspond to specific passive tracking devices108 (and/or the multi-mode tracking device 102 and/or the pairedtracking devices 106), where each device ID may be correlated to aparticular item or employee. In this way, the application can read thedevice IDs of devices in the vicinity of the user device 130 to identifyitems that are in the vicinity of the user device 130. Given the largeamounts of data that may be collected when there are lots of passivetracking devices 108 in the vicinity, edge processing may be performedto reduce the amount of data that is required. In some embodiments,machine learning can be used to identify items that don't move muchwithin a space, such that these items may only be reported if they arenot found during a particular scan of a particular location.

In some embodiments, the backend server system 130 may maintain aninventory of the items of a user and may maintain a profile of the user.In these embodiments, the backend server system 130 may send targetedadvertising emails and text messages to the person based on the inventorand/or profile. For example, upon learning the types of items kept atthe user's home or office, the backend server system 130 may determineadvertisements of similar products to send to the user.

In some embodiments, the tracking system 100 may be configured tooperate in conjunction with AR-enabled devices 140. In embodiments, thepassive tracking devices 108 can be read by any BT-enabled andUR-enabled user devices 140 having Bluetooth capabilities, includingAR-enabled smart glasses or voice-picking audio headsets. This allowsdirect reading of passive tracking devices 108 on products from theAR-enabled devices 140, which can then be factored into the process.Supplemental transmitters (e.g., exciters 110) can extend the range ofthe reading, but this may cause many more passive tracking devices 108in the vicinity to transmit beacons. In this scenario, an AR-enableddevice 140 may be unable to determine which passive tracking devices 108are in the near vicinity.

In some scenarios, AR-enabled devices 140 may not transmit sufficientpower to continually energize passive tags. WiFi access points,Bluetooth base stations, or other RF transmitters, however, may beconfigured to energize the passive tracking devices 108, while anAR-enabled device can receive the beacons from the passive trackingdevices 108. In some embodiments, these AR-enabled devices 140 maycontain a Bluetooth receiver configured with angle of arrival detectionto triangulate locations of passive tracking devices 108. In someembodiments, the location of each tagged item (e.g., items havingpassive tracking devices 140 affixed thereto) may be relayed to theAR-enabled device via an AR-enabled device cloud data manager (e.g., abackend server system. The AR-enabled device 140 may compare the taggeditem's location with its own location and direction and may display anindicia on a screen of the AR-enabled device to indicate where the itemis, when the item is determined to be in the field of view of theAR-enabled device 140.

In embodiments, an AR-enabled device cloud data manager may match up thedevice ID's of detected passive tracking devices 108 with the associateditem's visual identifiers such as shape, size, color, markings, etc.(which may be stored in memory and associated with the device ID). TheAR-enabled device 140 may highlight or outline the device in the displayof the AR-enabled display 140, and may match any data such as modelnumber, dates, expiration, correct/incorrect item in process, etc.

In embodiments, an AR-enabled device 140 may contain an infra-red orvisible light laser that may point to the item being looked at. TheAR-enabled device 140 may display a cross hair, outline, or otherindicia to indicate the location at which the laser is pointing of wherethe laser is pointed at. As discussed, a passive tracking device 108 maycontain a photo-detector that can detect light levels incident upon thepassive tracking device 108. Additionally or alternatively, the passivetracking device 108 may contain a temperature sensor that can detect arise in temperature when the laser light shines on the device 108 for aperiod of time. In such configurations, a BLE beacon may contain a fieldfor the photodetector light intensity state/value and/or the temperaturevalue. The reported Lux values can be self-normalizing for differentlight conditions when reading the BLE beacon before pointing the laserand while pointing. Modulating the light and implementing a low powermodulation detector (e.g., max min values over a short time frame (e.g.,100 msec)) may further identify the specific item being illuminated. Theinfrared light can penetrate through some packaging materials, such thateven embedded passive tracking devices 108 may be identified.

In embodiments, a low power accelerometer (e.g., MEMS accelerometer) maybe embedded in the passive tracking device 108. When the tagged item isdetected by an AR-enabled device 140, the passive tracking device 108may report its motion in the beacon. The AR-enabled device cloud datamanager may relay such detection to the AR-enabled device 140 as anidentification input.

In some embodiments, an AR-enabled device 140 may be configured to tracka user's eye gaze. In tracking the user's eye gaze, the AR-enableddevice 140 may determine a more accurate location at which the user isstaring. In these embodiments, the AR-enabled device 140 may beconfigured to display a detected item, only when the user is staring inthe direction of the detected item.

In some implementations, the tracking system 100 and/or backend serversystems 120 may be configured to maintain temperature logs on behalf ofpassive tracking devices 108. Traditional temperature monitoring tagsare read infrequently and thus need batteries to sample at regularintervals and store the data in a log. Purely passive devices are unableto sample and store when no power source is available. Thus, inembodiments, the passive tracking devices 108 may be energizedperiodically for the purpose of obtaining temperature data that can beused by an upstream device (e.g., an aggregator device, a multi-modetracking device 102, and/or a backend server system 120) to maintaintemperature logs on behalf of the tracking devices 108. If passivetracking devices 108 are read more often, then the passive trackingdevices 108 can take temperatures samples while energized and send thevalues out in respective beacons. A tracker (e.g., aggregator device 104and/or a multi-mode tracking device 102) can send the sampled value, atime stamp, and location information to the backend server system 120.The backend server system 120 and/or the tracker may utilize thisinformation to maintain a temperature log for each respective passivetracking device 108. While this is not a regular sampling, and only somepassive tracking devices 108 may be read at any given time, cloud dataanalysis can group readings from passive tracking devices 108 andreconstruct the temperature and location history of a whole group ofpassive tracking devices 108.

In general, asset trackers rely on connectivity for location. Assettrackers may use a combination of GN SS, WiFi, Cellular and Bluetoothconnectivity to obtain and transmit location information. These servicesare not always available and may unnecessarily consume power andresources. To mitigate these issues, in some embodiments, the trackingsystem 100 may implement inertial measurement unit (IML)-based activitydetection and tracking. In the same way that personal wearable activitytrackers determine when a wearer is swimming, walking or running, thedevice in the tracking system 100 would detect activities related toasset movement. In these embodiments, the tracking algorithms may bedesigned, for example, to: detect that an asset is being loaded orunloaded from a delivery truck or van; detect that an asset is loaded ina pallet; detect that a pallet is being built up; detect that a palletcontaining an asset is being wrapped or finished up; detect that atracking device in a pallet is moving in a warehouse; detect that aperson picks up and carries the asset; detect that an asset is droppedfrom a height; and the like. In some of these embodiments, the backendserver 120 and/or the tracking devices may sample the motion datareported by the tracking devices and may compare the motion data todifferent motion signatures to classify the type of movement. The systemmay implement one or more machine-learned models (e.g., neural networks)to classify the types of movement.

In some scenarios, radios integrated into low power battery-operatedconsumer or industrial devices need to be turned on periodically tocommunicate data or acquire location. A radio integrated into such adevice does not always have connectivity, and as such, may waste energy.Thus, in some embodiments, tracking system 100 that implements activitydetection may be used to characterize the radio connectivity of anenvironment, building, and storage facility in terms of activitydetection. As the tracking system 100 collects more data it will improveits prediction of when a particular radio can be turned on to have ahigher chance of obtaining connectivity. This knowledge can be used totrain other asset trackers within the same system, obtaining immediateresults without previous training. For example, a tracking device (e.g.,a multi-mode tracking device 102) may be trained to detect when it isbeing loaded into a truck for the first time, when it has a high chanceof connecting to obtaining WiFi connectivity but not LTE connectivity,and the like. Based on the activity detection, the tracking device(e.g., a multi-mode tracking device 102) may turn its WiFi capabilitieson or off. In another example, a tracking device associated with anasset carried on a train may determine that it has a low probability toobtain GNSS location. As such, the tracking device may never turn on itsradio until the asset is determined to be no longer on the train.

In some embodiments, the tracking devices (e.g., passive trackingdevices 108 or paired tracking devices 106) in the tracking system 100may implement antenna diversity management in order to maximize powerefficiency. In these embodiments, BLE beacons that support antennadiversity transmit the antenna being used in the advertising package. Areceiver from a receiving device (e.g., an aggregator 104) answers withan advertising response that contains the receive RSSI and antenna usedby the transmitted beacon. The tracking device (e.g., passive trackingdevice 108 or paired tracking device 106) uses this data to select thebest antenna for transmitting, whereby the device only transmits on theselected antenna for the next few (e.g., five) beacons, until the RSSIchanges significantly or the device doesn't obtain a response.

In some scenarios, it is difficult to locate an asset while movingthrough a supply chain or while in storage. Tracking devices today relyon individual “knowledge” of an asset's location. There can be manytracker devices deployed in a single location to track assets at anygiven time, but these tracking devices do not rely today on a sharedknowledge.

In some embodiments, the tracking system 100 may be configured to shareintelligence of individual tracking devices and/or data points collectedby the tracking devices to improve the location accuracy of nearbyassets. For example, the tracking devices may share pressure sensor dataamong many tracking devices. Low cost atmospheric pressure sensorsprovide relative pressure measurements. The relative nature of the datadoes not allow the tracking system to determine how high a pallet isstored in a warehouse, for example. By sharing the data of many otherasset tracking devices nearby, the backend server system 120 can createa virtual map of a space. In embodiments, the map may be augmented bymerging other sources of sensor data. For example, assets move on awarehouse at two levels, we can infer two floors. Moreover, stationaryassets have different pressure readings in between these two levels. Inthis example, the backend server system 120 can statistically inferpallet height or storage shelf height above the levels. Such estimationscan be calculated more accurately as more data is collected. Thedimensions to create a virtual map can be given by orientation,acceleration, bearing, temperature, pressure, humidity, ambient light,radio-based geolocation, laser interferometry, and the like.

It is desired to be able to track devices in many differentenvironments, and not just in controlled environments such as shippingenvironments or storage environments. The issue that arises, however,implementing tracking infrastructure across many different environmentsis an expensive approach and, due to power concerns, not alwaysfeasible. Thus, in some embodiments, user devices 160 may be configuredto discover tracking devices (e.g., passive tracking devices and/orpowered tracking devices) associated with tracked items and may reportthe discovery of such to a backend tracking system 120.

In some embodiments, the tracking devices may discover a tracking device(powered or passive) when it receives a short message from the trackingdevice. In embodiments, the tracking devices include powered trackingdevices that are configured to periodically announce their presence byemitting a short message containing a device identifier of the trackingdevice and any other suitable data. In some embodiments, the trackingdevices included passive tracking devices. In these embodiments, thepassive tracking devices may be energized by another device (e.g., by anRF signal emitted by the other device) and in response to beingenergized may emit a short message containing a device identifier of thetracking device and any other suitable data. In these embodiments, userdevices 160 may be configured to periodically emit a signal thatenergizes passive devices in its proximity. As a user of the user device160 moves (e.g., walks, runs, bikes, etc.) through an environment havinga tracked item or as a tracked item moves into the environment of a userdevice 160, the user device 160 may energize the passive trackingdevice, which emits the short message, in either scenario, a trackingdevice may transmit a short message containing beacon data such as adevice identifier of the tracking device and any other suitable data. Inresponse to receiving a short message from the tracking device, the userdevice 160 may push any beacon data received from a discovered trackingdevice to a backend tracking system 120. For example, the user device160 may transmit the device identifier of the tracking device and anyother data contained in the short message to the backend tracking system120. In embodiments, the user device 160 may also communicate itsgeolocation (e.g., a geolocation obtained from the GPS system of theuser device 160) with the beacon data to the backend tracking system120.

In embodiments, the backend tracking system 120 may maintain a locationprofile for all BLE beacon tagged items. In embodiments, a locationprofile may correspond to an item being tracked. The location profilemay indicate a set of one or more tracking devices that are associatedwith the tracked item (e.g., device identifiers of any items associatedwith the tracked item), geolocations of respective user devices 160 whenthey discovered a tracking device associated with the tracked item, andfor each respective geolocation, a time stamp indicating when thereporting user device 160 reported the discovery of a tracking devicethat is associated with the tracked item. The location profile mayinclude additional metadata as well, including a device type and/ordevice identifier of the user device 160 that reported a discovery, thedevice identifier of the tracking device that transmitted the shortmessage to the user device 160, and/or the like. In embodiments, thebackend tracking system 120 may update a location profile of a trackeditem in response to receiving a device identifier of a tracking deviceand a geolocation of a user device 160 from the user device 160. In someof these embodiments, the backend tracking system may aggregate the datain the location profile of a tracked item to determine any number ofsuitable insights on the tracked item. For example, the backend trackingsystem may determine a most recently known location of a tracked item, aroute of a tracked item, patterns relating to the movement of a trackeditem, and the like. The foregoing techniques may be applied to consumeritems and/or industrial items.

In some cases, tracked items may be in areas that are not typicallypopulated with user devices 160 or in areas where power issues are notof concern. For example, tracked items may be in environments such asindustrial environments, manufacturing environments, shippingenvironments, and/or supply chain environments. Thus, in someembodiments, specialized location collector node devices (or “collectornode devices”), such as fixed mount or mobile tracking devices may beinstalled in areas where more precise and timely location information isdesired. The collector node devices may operate in the same manner asthe user devices 160 described above, in that a collector node devicemay receive a short message emitted by a tracking device that includesbeacon data that indicates a device identifier of the tracking device.In response to receiving a short message, the collector node device mayreport the device identifier of the tracking device and a geolocationlocation of the collector node device to the backend tracking system120. The backend tracking system 120 may receive the device identifierof the tracking device and the geolocation of the collector node deviceand may update a location profile of a tracked item, in the mannerdescribed above.

Furthermore, in embodiments, multiple collector node devices may beplaced in the same environment and may have overlapping communicationranges, so as to improve the accuracy of a location estimate of atracked item. For example, two collector node devices may be placed ateither side of a room, whereby a tracking device in the middle of theroom may be in the communication range of both collector node devices,but a tracking device at either end of the room may only be in thecommunication range of one of the collector node devices. Thus, when thetracking device emits a short message that indicates the deviceidentifier of the tracking device and both collector node devices reportsuch an event to the backend tracking system 120, the backend trackingsystem 120 may determine that the tracking device is near the middle ofthe room; whereas when only one of the collector node devices reportsuch an event, the backend tracking system may determine that thetracking device is at one of the ends of the room.

In embodiments, the collector node devices are powered by a wiredconnection to a power source, and as such may be implemented with ahigher powered RF transmitter. In this way, the collector node devicesmay extend the read range of the collector node device and may detect agreater amount of tracking devices in the vicinity of the collector nodedevice.

In some scenarios, however, the available RF energy in an environmentmay not be sufficient to energize a passive tracking device, or even ifsufficient, the collector node device may have to harvest energy for along time between every passive tracking device. In some embodiments,the tracking system may include RF illuminators. The RF illuminators maybe placed in locations to extend the tag energizing range and/or toenable more user devices 160 to receive short messages from passivetracking devices. In embodiments, RF illuminators may be a simpletransmit only devices that do not communicate with a network. In someembodiments, the illuminators may include a wired power source (e.g., awall outlet) or a portable power source (e.g., battery). Theilluminators may transmit at a frequency selected from multipledifferent frequencies to provide the greatest amount of RF energywithout interfering with other bands. In embodiments, the illuminatorsmay use directional antennas to create desired energizing zones, wherebya tracking device that enters a desired energizing zone may broadcastthe short message to any user device 160 within a receiving range of thetracking devices. It is noted that the receiving range is typicallygreater in radius than the energizing zone. Therefore, user devices 160that are outside of the energizing zone may still be located in thereceiving zone.

In embodiments, the illuminators may include sensors and/or networkinterface devices to enable additional features. In embodiments, theilluminators may include network interface devices to enablecommunication with the backend tracking system and/or otherilluminators. In these embodiments, the backend tracking system and/oranother illuminator may transmit a command to the illuminator to beginemitting the RF energy signal or to stop transmitting the RF energysignal. In embodiments, the illuminator may include one or more motionsensors, whereby once motion is detected in the vicinity of theilluminator, the illuminator may begin emitting the RF energy signal. Inthese embodiments, the motion sensor triggers the illuminator to beginenergizing potential tracking devices in the vicinity, only when thereis motion detected, so as to record any tracking items that haverecently entered the energizing zone of the illuminator. In embodiments,the illuminators may also transmit commands to the passive trackingdevices over the RF energy signal. These commands may include requestsfor specific types of data (e.g., temperature data or light data)collected by sensors that are integrated into the tracking devices.

In embodiments, the tracking devices may include embedded sensors, suchas temperature sensors, humidity sensors, light sensors, inertialsensors, shock sensors, and/or chemical sensors. These sensors collectand store data until a communication link is established, therebyallowing the collected data to be uploaded. These tracking devices,however can be much more expensive than passive tracking devices withoutsensors and may require expensive WAN cellular models or may require aninfrastructure of readers to download the collected data from thetracking devices. A passive tracking device does not typically have thecapability to store sensor data, even when the tracking device hasenough RF energy harvested to take a sample from a sensor.

To assuage these concerns, in some embodiments, the various sensors maybe designed to embed and operate in a passive tracking device. In theseembodiments, a passive tracking device may be configured to transmit thesensor data immediately and repeatedly when there the passive trackingdevice has harvested sufficient power to transmit this data. The sensordata is collected by any user device 160 within receiving range of thepassive tracking device. Thus, any user device 160 that is within theproximity of a passive tracking device may receive the sensor data fromthe passive tracking device and may upload the collected sensor data tothe backend tracking system 120. While the likelihood of any one userdevice 160 receiving a short message containing the collected data isrelatively low and random, the aggregated data log from the user devicespassing by and uploading the sensor data to the backend server maynevertheless provide ample data.

One issue that arises with the user of user devices 160 to tracktracking items/tracking devices is that the locations of the userdevices 160 does not give the full picture of temporal events at certaintypes of locations or events, such as concerts, lunch wagons, kiosks,emergency response events, and the like.

In embodiments, the passive tracking devices may be configured toprovide contextual data in a short message. Contextual data may includea code or other indicia that provides temporal information at a givenlocation. Passive tracking devices (e.g., tags) applied toapplication-specific vehicles such as fire engines, ambulances, policecars, busses, lunch wagons, delivery trucks, etc., may provide temporalinformation that would not be available otherwise. Similarly, tagsapplied to temporary structures (e.g., concert venues, kiosks, racefinish lines, etc.) may provide advertising opportunities for businesson social media and/or may provide contextual information for taggeditems.

In certain scenarios, it may be desirable to tag important items, suchas important documents that require visual signage and/or notaryauthentication or valuable items such as jewelry, artwork, and expensiveclothing items that may require certificates of authenticity. Inembodiments, a tracking device may be configured to performauthentication using a distributed ledger, such as Blockchain. In theseembodiments, a passive tracking device (e.g., a tag) may include adevice identifier or other value that corresponds to an entry that isstored on the distributed register, whereby the entry associates thepassive tracking device with a party (e.g., a signer of the document, amaker of a work of art, the issuer of a bond, the seller of an expensiveclothing item). In this way, a party wishing to establish authenticitymay adhere a passive tracking device (e.g., a tag) to an important itemthat is being provided to another party. The other party may scan thepassive tracking device to authenticate the item. For example, inresponse to scanning the item with a user device 160, the user device160 may request that a device storing a cryptographic ledgercorresponding to the tag verify that there is a block having the deviceidentifier or other indicia associated with the tag, and that the tag isassociated with the party establishing the authenticity.

In some embodiments, passive BLE tags (such as the passive trackingdevices discussed above) may be configured as low cost hardware cryptowallets. In these embodiments, a passive BLE tag may store one or moreprivate keys/public keys of an owner of the tag, whereby the privatekeys are associated with credit card and/or crypto currency accounts ofthe user. The BLE tag may be energized/scanned at a point of sale, whichmay prompt the user to authorize a transaction with respect to anaccount of the user that is associated with the tag.

Detailed embodiments of the present disclosure are disclosed herein;however, it is to be understood that the disclosed embodiments aremerely exemplary of the disclosure, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present disclosure in virtually anyappropriately detailed structure.

The terms “a” or “an,” as used herein, are defined as one or more thanone. The term “another,” as used herein, is defined as at least a secondor more. The terms “including” and/or “having,” as used herein, aredefined as comprising (i.e., open transition).

While only a few embodiments of the present disclosure have been shownand described, it will be obvious to those skilled in the art that manychanges and modifications may be made thereunto without departing fromthe spirit and scope of the present disclosure as described in thefollowing claims. All patent applications and patents, both foreign anddomestic, and all other publications referenced herein are incorporatedherein in their entireties to the full extent permitted by law.

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software, program codes,and/or instructions on a processor. The present disclosure may beimplemented as a method on the machine, as a system or apparatus as partof or in relation to the machine, or as a computer program productembodied in a computer readable medium executing on one or more of themachines. In embodiments, the processor may be part of a server, cloudserver, client, network infrastructure, mobile computing platform,stationary computing platform, or other computing platforms. A processormay be any kind of computational or processing device capable ofexecuting program instructions, codes, binary instructions and the like.The processor may be or may include a signal processor, digitalprocessor, embedded processor, microprocessor or any variant such as aco-processor (math co-processor, graphic co-processor, communicationco-processor and the like) and the like that may directly or indirectlyfacilitate execution of program code or program instructions storedthereon. In addition, the processor may enable execution of multipleprograms, threads, and codes. The threads may be executed simultaneouslyto enhance the performance of the processor and to facilitatesimultaneous operations of the application. By way of implementation,methods, program codes, program instructions and the like describedherein may be implemented in one or more thread. The thread may spawnother threads that may have assigned priorities associated with them;the processor may execute these threads based on priority or any otherorder based on instructions provided in the program code. The processor,or any machine utilizing one, may include non-transitory memory thatstores methods, codes, instructions and programs as described herein andelsewhere. The processor may access a non-transitory storage mediumthrough an interface that may store methods, codes, and instructions asdescribed herein and elsewhere. The storage medium associated with theprocessor for storing methods, programs, codes, program instructions orother type of instructions capable of being executed by the computing orprocessing device may include but may not be limited to one or more of aCD-ROM, DVD, memory, hard disk, flash drive, RAM, ROM, cache and thelike.

A processor may include one or more cores that may enhance speed andperformance of a multiprocessor. In embodiments, the process may be adual core processor, quad core processors, other chip-levelmultiprocessor and the like that combine two or more independent cores(called a die).

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software on a server,client, firewall, gateway, hub, router, or other such computer and/ornetworking hardware. The software program may be associated with aserver that may include a file server, print server, domain server,Internet server, intranet server, cloud server, and other variants suchas secondary server, host server, distributed server and the like. Theserver may include one or more of memories, processors, computerreadable media, storage media, ports (physical and virtual),communication devices, and interfaces capable of accessing otherservers, clients, machines, and devices through a wired or a wirelessmedium, and the like. The methods, programs, or codes as describedherein and elsewhere may be executed by the server. In addition, otherdevices required for execution of methods as described in thisapplication may be considered as a part of the infrastructure associatedwith the server.

The server may provide an interface to other devices including, withoutlimitation, clients, other servers, printers, database servers, printservers, file servers, communication servers, distributed servers,social networks, and the like. Additionally, this coupling and/orconnection may facilitate remote execution of program across thenetwork. The networking of some or all of these devices may facilitateparallel processing of a program or method at one or more locationwithout deviating from the scope of the disclosure. In addition, any ofthe devices attached to the server through an interface may include atleast one storage medium capable of storing methods, programs, codeand/or instructions. A central repository may provide programinstructions to be executed on different devices. In thisimplementation, the remote repository may act as a storage medium forprogram code, instructions, and programs.

The software program may be associated with a client that may include afile client, print client, domain client, Internet client, intranetclient and other variants such as secondary client, host client,distributed client and the like. The client may include one or more ofmemories, processors, computer readable media, storage media, ports(physical and virtual), communication devices, and interfaces capable ofaccessing other clients, servers, machines, and devices through a wiredor a wireless medium, and the like. The methods, programs, or codes asdescribed herein and elsewhere may be executed by the client. Inaddition, other devices required for execution of methods as describedin this application may be considered as a part of the infrastructureassociated with the client.

The client may provide an interface to other devices including, withoutlimitation, servers, other clients, printers, database servers, printservers, file servers, communication servers, distributed servers andthe like. Additionally, this coupling and/or connection may facilitateremote execution of program across the network. The networking of someor all of these devices may facilitate parallel processing of a programor method at one or more location without deviating from the scope ofthe disclosure. In addition, any of the devices attached to the clientthrough an interface may include at least one storage medium capable ofstoring methods, programs, applications, code and/or instructions. Acentral repository may provide program instructions to be executed ondifferent devices. In this implementation, the remote repository may actas a storage medium for program code, instructions, and programs.

The methods and systems described herein may be deployed in part or inwhole through network infrastructures. The network infrastructure mayinclude elements such as computing devices, servers, routers, hubs,firewalls, clients, personal computers, communication devices, routingdevices and other active and passive devices, modules and/or componentsas known in the art. The computing and/or non-computing device(s)associated with the network infrastructure may include, apart from othercomponents, a storage medium such as flash memory, buffer, stack, RAM,ROM and the like. The processes, methods, program codes, instructionsdescribed herein and elsewhere may be executed by one or more of thenetwork infrastructural elements. The methods and systems describedherein may be adapted for use with any kind of private, community, orhybrid cloud computing network or cloud computing environment, includingthose which involve features of software as a service (SaaS), platformas a service (PaaS), and/or infrastructure as a service (IaaS).

The methods, program codes, and instructions described herein andelsewhere may be implemented on a cellular network having multiplecells. The cellular network may either be frequency division multipleaccess (FDMA) network or code division multiple access (CDMA) network.The cellular network may include mobile devices, cell sites, basestations, repeaters, antennas, towers, and the like. The cell networkmay be a GSM, GPRS, 3G, EVDO, mesh, or other networks types.

The methods, program codes, and instructions described herein andelsewhere may be implemented on or through mobile devices. The mobiledevices may include navigation devices, cell phones, mobile phones,mobile personal digital assistants, laptops, palmtops, netbooks, pagers,electronic books readers, music players and the like. These devices mayinclude, apart from other components, a storage medium such as a flashmemory, buffer, RAM, ROM and one or more computing devices. Thecomputing devices associated with mobile devices may be enabled toexecute program codes, methods, and instructions stored thereon.Alternatively, the mobile devices may be configured to executeinstructions in collaboration with other devices. The mobile devices maycommunicate with base stations interfaced with servers and configured toexecute program codes. The mobile devices may communicate on apeer-to-peer network, mesh network, or other communications network. Theprogram code may be stored on the storage medium associated with theserver and executed by a computing device embedded within the server.The base station may include a computing device and a storage medium.The storage device may store program codes and instructions executed bythe computing devices associated with the base station.

The computer software, program codes, and/or instructions may be storedand/or accessed on machine readable media that may include: computercomponents, devices, and recording media that retain digital data usedfor computing for some interval of time; semiconductor storage known asrandom access memory (RAM); mass storage typically for more permanentstorage, such as optical discs, forms of magnetic storage like harddisks, tapes, drums, cards and other types; processor registers, cachememory, volatile memory, non-volatile memory; optical storage such asCD, DVD; removable media such as flash memory (e.g., USB sticks orkeys), floppy disks, magnetic tape, paper tape, punch cards, standaloneRAM disks, Zip drives, removable mass storage, off-line, and the like;other computer memory such as dynamic memory, static memory, read/writestorage, mutable storage, read only, random access, sequential access,location addressable, file addressable, content addressable, networkattached storage, storage area network, bar codes, magnetic ink, and thelike.

The methods and systems described herein may transform physical and/orintangible items from one state to another. The methods and systemsdescribed herein may also transform data representing physical and/orintangible items from one state to another.

The elements described and depicted herein, including in flowcharts andblock diagrams throughout the figures, imply logical boundaries betweenthe elements. However, according to software or hardware engineeringpractices, the depicted elements and the functions thereof may beimplemented on machines through computer executable media having aprocessor capable of executing program instructions stored thereon as amonolithic software structure, as standalone software modules, or asmodules that employ external routines, code, services, and so forth, orany combination of these, and all such implementations may be within thescope of the present disclosure. Examples of such machines may include,but may not be limited to, personal digital assistants, laptops,personal computers, mobile phones, other handheld computing devices,medical equipment, wired or wireless communication devices, transducers,chips, calculators, satellites, tablet PCs, electronic books, gadgets,electronic devices, devices having artificial intelligence, computingdevices, networking equipment, servers, routers and the like.Furthermore, the elements depicted in the flowchart and block diagramsor any other logical component may be implemented on a machine capableof executing program instructions. Thus, while the foregoing drawingsand descriptions set forth functional aspects of the disclosed systems,no particular arrangement of software for implementing these functionalaspects should be inferred from these descriptions unless explicitlystated or otherwise clear from the context. Similarly, it will beappreciated that the various steps identified and described above may bevaried and that the order of steps may be adapted to particularapplications of the techniques disclosed herein. All such variations andmodifications are intended to fall within the scope of this disclosure.As such, the depiction and/or description of an order for various stepsshould not be understood to require a particular order of execution forthose steps, unless required by a particular application, or explicitlystated or otherwise clear from the context.

The methods and/or processes described above, and steps associatedtherewith, may be realized in hardware, software or any combination ofhardware and software suitable for a particular application. Thehardware may include a general-purpose computer and/or dedicatedcomputing device or specific computing device or particular aspect orcomponent of a specific computing device. The processes may be realizedin one or more microprocessors, microcontrollers, embeddedmicrocontrollers, programmable digital signal processors or otherprogrammable devices, along with internal and/or external memory. Theprocesses may also, or instead, be embodied in an application specificintegrated circuit, a programmable gate array, programmable array logic,or any other device or combination of devices that may be configured toprocess electronic signals. It will further be appreciated that one ormore of the processes may be realized as a computer executable codecapable of being executed on a machine-readable medium. The computerexecutable code may be created using a structured programming languagesuch as C, an object oriented programming language such as C++, or anyother high-level or low-level programming language (including assemblylanguages, hardware description languages, and database programminglanguages and technologies) that may be stored, compiled or interpretedto run on one of the above devices, as well as heterogeneouscombinations of processors, processor architectures, or combinations ofdifferent hardware and software, or any other machine capable ofexecuting program instructions.

Thus, in one aspect, methods described above and combinations thereofmay be embodied in computer executable code that, when executing on oneor more computing devices, performs the steps thereof. In anotheraspect, the methods may be embodied in systems that perform the stepsthereof, and may be distributed across devices in a number of ways, orall of the functionality may be integrated into a dedicated, standalonedevice or other hardware. In another aspect, the means for performingthe steps associated with the processes described above may include anyof the hardware and/or software described above. All such permutationsand combinations are intended to fall within the scope of the presentdisclosure.

While the disclosure has been disclosed in connection with the preferredembodiments shown and described in detail, various modifications andimprovements thereon will become readily apparent to those skilled inthe art. Accordingly, the spirit and scope of the present disclosure isnot to be limited by the foregoing examples but is to be understood inthe broadest sense allowable by law.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the disclosure (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitations of ranges ofvalues herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein may be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate the disclosure and does not pose a limitation on the scope ofthe disclosure unless otherwise claimed. No language in thespecification should be construed as indicating any non-claimed elementas essential to the practice of the disclosure.

While the foregoing written description enables one skilled in the artto make and use what is considered presently to be the best modethereof, those skilled in the art will understand and appreciate theexistence of variations, combinations, and equivalents of the specificembodiment, method, and examples herein. The disclosure should thereforenot be limited by the above-described embodiment, method, and examples,but by all embodiments and methods within the scope and spirit of thedisclosure.

Any element in a claim that does not explicitly state “means for”performing a specified function, or “step for” performing a specifiedfunction, is not to be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. § 112(f). In particular, any use of “step of” inthe claims is not intended to invoke the provision of 35 U.S.C. §112(f).

Persons skilled in the art may appreciate that numerous designconfigurations may be possible to enjoy the functional benefits of theinventive systems. Thus, given the wide variety of configurations andarrangements of embodiments of the present invention the scope of theinvention is reflected by the breadth of the claims below rather thannarrowed by the embodiments described above.

What is claimed is:
 1. A tracking system comprising: a plurality oftracking devices, each tracking device of the plurality of trackingdevice having a device identifier that uniquely identifies the trackingdevice from other tracking devices of the plurality of tracking devices,wherein each tracking device is configured to transmit a short messageindicating the device identifier of the tracking device via a shortrange communication medium; a backend tracking system that maintains aplurality of location profiles, each location profile corresponding to arespective tracked item that is associated with one or more trackingdevices of the plurality of tracking devices and that maintains reportedlocations of the tracked item and a timestamp corresponding to eachreported location; a plurality of tracking modules, wherein eachtracking module is installed on a respective user device, and isconfigured to: receive a transmitted short message from a proximatetracking device of the plurality of tracking devices that is within areceiving range of the user device on which the tracking module isinstalled, the short message indicating the device identifier of theproximate tracking device; and determine a geolocation of the userdevice on which the tracking module is installed; and transmit thedevice identifier of the proximate tracking device and the geolocationof the user device; and wherein the backend tracking system isconfigured to update the location profile of a proximate tracked itemassociated with the proximate tracking device based on geolocation ofthe user device, the device identifier of the proximate tracking device,and a corresponding timestamp.
 2. The system of claim 1, wherein eachtracking module is further configured to generate the correspondingtimestamp in response to receiving the transmitted short message and isconfigured to transmit the timestamp to the backend tracking system withthe geolocation and the device identifier.
 3. The system of claim 1,wherein the backend tracking system is configured to generate thecorresponding timestamp in response to receiving the geolocation of theuser device and the device identifier of the proximate tracking device.4. The system of claim 1, wherein the plurality of tracking devicesincludes one or more passive tracking devices, wherein each passivetracking device comprises an energizing circuit that energizes thepassive tracking device in response to a radio frequency signal.
 5. Thesystem of claim 4, wherein each tracking module is configured to commandthe user device on which the tracking module is installed to emit theradio frequency signal that energizes proximate passive trackingdevices.
 6. The system of claim 4, further comprising: a plurality ofradio frequency illuminators, wherein each radio frequency illuminatorincludes an RF circuit, including an RF transmitter that emits arespective radio frequency signal that energizes proximate passivetracking devices in an energizing zone of the illuminator.
 7. The systemof claim 6, wherein the RF transmitter of each radio frequencyilluminator is a directional antenna.
 8. The system of claim 1, whereineach tracking module is configured to listen for short messages frompassive tracking devices in proximity to the user device on which thetracking module is installed.
 9. A passive tracking device comprising: afirst antenna that transmits response signals in a first frequency band;a second antenna that receives energizing signals in a second frequencyband; an energy harvest module that receives an energizing signal from aremote device via the second antenna and converts the energizing signalfrom RF electrical energy to DC electrical energy that energizes thepassive tracking device; a transmission module that modulates a responsesignal for transmission in the first frequency band and outputs themodulated response signal to the first antenna for transmission inaccordance with a communication protocol, the response signal includinga message indicating a device identifier of the passive tracking device,wherein the transmission module includes a bulk acoustic wave referenceoscillator that produces an output frequency, the bulk acoustic wavereference oscillator including a bulk acoustic wave delay reference, andwherein the transmission module modulates the response signal such thatthe response signal has a carrier frequency based on the outputfrequency of the bulk acoustic wave reference oscillator.
 10. Thepassive tracking device of claim 9, wherein the bulk acoustic wavereference oscillator includes a master clock, a time differencedetector, a phase frequency detection module, and a loop filter.
 11. Thepassive tracking device of claim 10, wherein: the master clock outputsthe output frequency to other components of the first transmissionmodule for use as a carrier frequency reference and outputs the outputfrequency to the time difference detector; a time difference detectorthat detects a plurality of echoes of the bulk acoustic wave delayreference, generates a first echo signal and a second echo signal basedon a first echo and a second echo of the plurality of echoes,respectively, compares the first echo signal to the output frequency togenerate an end pulse, and outputs both the end pulse and the secondecho signal to the phase frequency detection module; a phase frequencydetection module that compares a phase of the end pulse to a phase ofthe second echo signal, generates a pump pulse, and generates a currentbased on the pump pulse; and a loop filter that amplifies the currentand outputs the amplified current to the master clock, thereby forming afeedback loop and correcting the output frequency.
 12. The passivetracking device of claim 11, wherein: the pump pulse is a pump-downpulse when the phase of the end pulse is earlier than the phase of thesecond echo signal, and the phase frequency detection module generatesnegative current based on the pump-down pulse.
 13. The passive trackingdevice of claim 11, wherein: the pump pulse is a pump-up pulse when thephase of the end pulse is later than the phase of the second echosignal, and the phase frequency detection module generates positivecurrent based on the pump-up pulse.
 14. The passive tracking device ofclaim 11, wherein: the time difference detector includes a temperaturecompensation module that receives a temperature reading and outputs atemperature adjustment signal to the time difference detector based onthe temperature reading; the time difference detector adjusts one orboth of the echo signals and the end pulse based on the temperatureadjustment signal.
 15. The passive tracking device of claim 9, whereinthe transmission module modulates the response signal such that theresponse signal has a carrier frequency substantially equal to a factorof the output frequency of the bulk acoustic wave reference oscillator.16. The passive tracking device of claim 9, wherein the transmissionmodule is a first transmission module, the response signals are firstresponse signals, the energizing signals are first energizing signals,the communication protocol is a first communication protocol, themessage is a first message, and the device identifier is a first deviceidentifier.
 17. The passive tracking device of claim 16, furthercomprising: a third antenna that both transmits second response signalsand receives second energizing signals in a third frequency band; asecond transmission module that prepares a second response signal fortransmission in the third frequency band and facilitates transmission ofthe prepared second response signals by toggling impedance of the thirdantenna when the passive tracking device operates in a second mode inaccordance with a second communication protocol, and wherein the secondresponse signal includes a second message indicating a second deviceidentifier of the passive tracking device; and a mode selection modulethat determines whether the passive tracking device is to operate in thefirst mode or the second mode based on a received energizing signal froma remote device via the second antenna and/or the third antenna.
 18. Thepassive tracking device of claim 17, wherein the first frequency band isequal to the second frequency band.